{"id":2503,"date":"2026-09-04T22:04:47","date_gmt":"2026-09-04T20:04:47","guid":{"rendered":"https:\/\/equilibriumpsychotherapy.net\/?p=2503"},"modified":"2026-09-18T11:01:30","modified_gmt":"2026-09-18T09:01:30","slug":"surprisingly-busy-business-of-sleeping","status":"publish","type":"post","link":"https:\/\/equilibriumpsychotherapy.net\/hr\/surprisingly-busy-business-of-sleeping\/","title":{"rendered":"The Surprisingly Busy Business of Sleeping"},"content":{"rendered":"\n<style>\n\/* The accent is a light-background device. 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She writes both halves every time, and in the glymphatic section\n   she names the move herself - \"The first statement is interesting science.\n   The second is a little too tidy.\"\n\n   TWO STATEMENTS SIDE BY SIDE, NOT AN ARROW FROM ONE TO THE OTHER. The first\n   version of this component put the popular claim on the left and the honest\n   version on the right with an arrow between them, which reads as \"actually\" -\n   and that is a frame the article does not always use. In section 14 she gives\n   the reasonable statement FIRST and the tidy one second; in section 16 she\n   gives the deflation first and the correction to it second. An arrow would\n   have forced her sentences into an order she did not write them in, twice.\n\n   So the component takes two sides, each side keeps whichever ground its\n   content earns, and the divider is a hairline rather than a direction. 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 for(var i=0;i<tops.length;i++){ if(tops[i]){ if(tops[i].offsetTop<=y) cur=i; } }  if(cur!==last){    links.forEach(function(a,i){a.classList.toggle(\"on\",i===cur);});    last=cur;  }  if(btn){    var h=document.documentElement.scrollHeight-window.innerHeight;    var far=false; if(h>0){far=window.scrollY\/h>0.35;}    btn.classList.toggle(\"on\",far);  }};addEventListener(\"scroll\",sync,{passive:true});addEventListener(\"resize\",sync);sync();if(btn)btn.addEventListener(\"click\",function(){  window.scrollTo({top:0,behavior:RM?\"auto\":\"smooth\"});});}if(document.readyState===\"loading\"){document.addEventListener(\"DOMContentLoaded\",init);}else{init();}})();<\/script>\n\n\n\n<div class=\"wp-block-group alignfull eqp has-global-padding is-layout-constrained wp-container-core-group-is-layout-69fa9525 wp-block-group-is-layout-constrained\" style=\"margin-top:0;margin-bottom:0;padding:0px 22px\">\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n<div style=\"color:#5a6b7d;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.455), 18px);font-style:normal;font-weight:400;margin-top:54px;margin-bottom:0\" class=\"has-link-color wp-elements-1 wp-block-post-date has-text-color has-work-sans-regular-font-family\"><time datetime=\"2026-09-04T22:04:47+02:00\">4 rujna, 2026<\/time><\/div>\n\n<div style=\"color:#5a6b7d;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.455), 18px);font-style:normal;font-weight:700;text-transform:uppercase;margin-top:0;margin-bottom:0\" class=\"taxonomy-category has-link-color wp-elements-2 wp-block-post-terms has-text-color has-work-sans-regular-font-family\"><a href=\"https:\/\/equilibriumpsychotherapy.net\/hr\/category\/body-and-mind\/\" rel=\"tag\">Body and Mind<\/a><span class=\"wp-block-post-terms__separator\">, <\/span><a href=\"https:\/\/equilibriumpsychotherapy.net\/hr\/category\/deep-dive\/\" rel=\"tag\">Deep Dive<\/a><\/div>\n\n\n<h1 class=\"wp-block-heading has-text-color has-playfair-display-font-family\" id=\"top\" style=\"color:#2b302f;margin-top:12px;margin-bottom:14px;font-size:clamp(24.034px, 1.502rem + ((1vw - 3.2px) * 1.814), 40px);font-style:normal;font-weight:800;line-height:1.15\">The Surprisingly Busy Business of Sleeping<\/h1>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#4b5560;margin-top:0;margin-bottom:22px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.55\">What actually happens while you\u2019re asleep<span style=\"color:#29538e;font-size:1.18em;font-weight:600;padding:0 .18em;line-height:1\">+<\/span>why your brain cares so much about getting enough of it<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#5a6b7d;margin-top:0;margin-bottom:0;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.114), 15px);line-height:1.5\"><strong style=\"color:#29538e\">24 minute read<\/strong> &nbsp;&middot;&nbsp; 5,461 words<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family eq-drop wp-block-paragraph\" style=\"color:#1f2b2d;margin-top:46px;margin-bottom:26px;font-size:clamp(14.642px, 0.915rem + ((1vw - 3.2px) * 0.836), 22px);line-height:1.62\">There is something slightly strange about sleep.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">We spend roughly a third of our lives doing it, and yet from the outside, it looks like we\u2019re doing almost nothing. You lie down, close your eyes, become largely unavailable to the outside world, and several hours later you wake up and carry on with your day. It is very easy to think of sleep as a pause. Biologically, though, it is anything but.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">While you\u2019re asleep, your brain moves through several distinct states of activity. Memories are being processed and reorganized. Hormones follow different patterns. Your immune system interacts with the sleep state. Your cardiovascular system changes its workload. Your metabolism shifts. Neural connections are being adjusted. The way you respond to emotional information the next day can be affected by what happened during the night.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Even the way you experience pain can change depending on how well you\u2019ve been sleeping. So although you are not consciously doing very much, your body certainly isn\u2019t sitting around waiting for morning. <strong class=\"eqb\">Sleep is a very active biological state<\/strong>. We just happen to experience most of that activity from the inside of a dream, or not experience it consciously at all.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<style>\n\/* The short version. Ground taken one step deeper than the article's accent so\n   white type sits comfortably on it, and kept clearly blue so it does not read\n   as the same object as the near-black closing slab (#17273d). The warm mark on\n   the numerals and the rule is drawn from this article's own caveat cream. *\/\n.eqp .eq-short{background:#1c3f6b;border-radius:22px;padding:clamp(30px,4vw,50px);margin:44px 0 12px;\n  color:#fff;font-family:\"Work Sans\",system-ui,sans-serif}\n.eqp .eq-short *{box-sizing:border-box}\n.eqp .eq-short .eyebrow{font-size:12px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;\n  color:#e8c07a;margin:0 0 14px}\n\/* No max-width on the hook or the closing line: both are two or three lines of\n   introduction, not sustained reading, and capping them leaves a visible column\n   of dead space down the right while the items below run full width. *\/\n.eqp .eq-short .hook{font:400 clamp(19px,1.95vw,22px)\/1.55 \"Work Sans\",sans-serif;color:#e6eefa;\n  margin:0 0 34px}\n.eqp .eq-short .hook b{color:#fff;font-weight:700}\n.eqp .eq-short ol{list-style:none;margin:0;padding:0;\n  display:grid;grid-template-columns:repeat(auto-fit,minmax(310px,1fr));gap:26px 44px}\n.eqp .eq-short li{margin:0;display:grid;grid-template-columns:auto 1fr;gap:15px;align-items:start}\n.eqp .eq-short .n{font:800 22px\/1.15 \"Playfair Display\",Georgia,serif;color:#e8c07a;\n  font-variant-numeric:tabular-nums}\n.eqp .eq-short .c{font:700 18px\/1.4 \"Work Sans\",sans-serif;color:#fff;margin:0 0 5px}\n.eqp .eq-short .s{font:400 15.5px\/1.55 \"Work Sans\",sans-serif;color:#bed0e8;margin:0}\n.eqp .eq-short .close{margin:36px 0 0;padding-top:26px;border-top:1px solid rgba(232,192,122,.30);\n  display:flex;align-items:baseline;gap:13px}\n.eqp .eq-short .close svg{flex:0 0 auto;width:15px;height:15px;color:#e8c07a;transform:translateY(2px)}\n.eqp .eq-short .close p{margin:0;font:400 16.5px\/1.6 \"Work Sans\",sans-serif;color:#d5e2f2}\n.eqp .eq-short .close b{color:#fff;font-weight:700}\n@media(max-width:560px){\n  .eqp .eq-short ol{grid-template-columns:1fr;gap:22px}\n  .eqp .eq-short li{gap:12px}\n}\n<\/style>\n<div class=\"eq-short\"><p class=\"eyebrow\">The short version<\/p><p class=\"hook\">Sleep has picked up two opposite reputations: wasted time you can borrow against when life gets busy, or one more thing to optimise with scores and supplements. <b>Neither is what the research describes.<\/b> Six things worth knowing before the long version.<\/p><ol><li><span class=\"n\">01<\/span><div><p class=\"c\">You can get used to too little sleep. That is not the same as being fine.<\/p><p class=\"s\">Humans become surprisingly good at living with sleep restriction, and you may stop noticing quite how tired you are once it has become your normal. Attention, reaction time and memory do not necessarily come back with you.<\/p><\/div><\/li><li><span class=\"n\">02<\/span><div><p class=\"c\">Sleep is part of learning, not what you do once the work is finished.<\/p><p class=\"s\">An all-nighter buys more hours of exposure to the material while cutting into the processes that consolidate it. The work is not over when you close the textbook.<\/p><\/div><\/li><li><span class=\"n\">03<\/span><div><p class=\"c\">A bad night does not change the problem. It changes the brain you bring to it.<\/p><p class=\"s\">Insufficient sleep can increase emotional reactivity and alter how the regulating regions talk to the reacting ones. The same difficult conversation can simply take more effort to get through.<\/p><\/div><\/li><li><span class=\"n\">04<\/span><div><p class=\"c\">Poor sleep can make pain hurt more.<\/p><p class=\"s\">Sleep deprivation can increase sensitivity to painful stimuli, and in people living with persistent pain, disturbed sleep and greater pain burden turn up together consistently. The tissue has not changed. The processing has.<\/p><\/div><\/li><li><span class=\"n\">05<\/span><div><p class=\"c\">Your ring is not a sleep laboratory.<\/p><p class=\"s\">Wearables infer sleep from movement and heart rate. They are reasonable at estimating how long you slept and much weaker at telling REM from deep sleep. There is even a word, orthosomnia, for worrying yourself out of sleep over the numbers.<\/p><\/div><\/li><li><span class=\"n\">06<\/span><div><p class=\"c\">Lying awake for months is not a willpower problem.<\/p><p class=\"s\">Insomnia can maintain itself: you go to bed expecting not to sleep, start counting the hours left, and the bed stops meaning sleep. That is why CBT for insomnia is a first-line treatment rather than a longer list of sleep hygiene rules.<\/p><\/div><\/li><\/ol><div class=\"close\"><svg viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M2 6h8M6.5 2.5 10 6l-3.5 3.5\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><p>What follows is the long version: <b>what each of those rests on, and where the evidence stops.<\/b> Including the parts sleep science has not settled, which is more of it than the internet suggests, and the unglamorous things that actually help.<\/p><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-dffd5825 wp-block-group-is-layout-constrained\" style=\"border-color:#e2e8f0;border-width:1.5px;border-style:solid;border-radius:22px;background-color:#f7fafb;margin-top:56px;margin-bottom:20px;padding:40px 44px 34px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#5a6b7d;margin-top:0;margin-bottom:22px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THIS ARTICLE COVERS &middot; EIGHT PARTS<\/p>\n\n\n\n<div class=\"wp-block-rank-math-toc-block\">\n<div class=\"eq-toc\"><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 1<\/span><a class=\"ttl\" href=\"#part-1\">The hours are not the whole story<\/a><span class=\"cnt\"><span class=\"sec\">2 sections<\/span><span class=\"sep\"> &middot; <\/span>2 min<\/span><\/summary><ul><li><a href=\"#so-how-much-sleep-do-we-actually-need\">So, how much sleep do we actually need?<\/a><\/li><li><a href=\"#sleep-is-not-one-single-state\">Sleep is not one single state<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 2<\/span><a class=\"ttl\" href=\"#part-2\">Two systems decide when you sleep<\/a><span class=\"cnt\"><span class=\"sec\">3 sections<\/span><span class=\"sep\"> &middot; <\/span>3 min<\/span><\/summary><ul><li><a href=\"#your-brain-has-an-internal-clock\">Your brain has an internal clock<\/a><\/li><li><a href=\"#why-does-sleep-pressure-build\">Why does sleep pressure build?<\/a><\/li><li><a href=\"#and-then-you-fall-asleep\">And then you fall asleep<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 3<\/span><a class=\"ttl\" href=\"#part-3\">Your brain is working on the day<\/a><span class=\"cnt\"><span class=\"sec\">3 sections<\/span><span class=\"sep\"> &middot; <\/span>3 min<\/span><\/summary><ul><li><a href=\"#your-brain-does-not-simply-store-memories\">Your brain does not simply \u201cstore\u201d memories<\/a><\/li><li><a href=\"#this-is-why-all-nighters-are-such-a-questionable-strategy\">This is why all-nighters are such a questionable strategy<\/a><\/li><li><a href=\"#and-then-there-is-rem-sleep\">And then there is REM sleep<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 4<\/span><a class=\"ttl\" href=\"#part-4\">A bad night changes the next day<\/a><span class=\"cnt\"><span class=\"sec\">2 sections<\/span><span class=\"sep\"> &middot; <\/span>2 min<\/span><\/summary><ul><li><a href=\"#sleep-changes-the-way-you-process-emotions\">Sleep changes the way you process emotions<\/a><\/li><li><a href=\"#sleep-and-stress-have-a-complicated-relationship\">Sleep and stress have a complicated relationship<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 5<\/span><a class=\"ttl\" href=\"#part-5\">Your body is not resting either<\/a><span class=\"cnt\"><span class=\"sec\">3 sections<\/span><span class=\"sep\"> &middot; <\/span>3 min<\/span><\/summary><ul><li><a href=\"#your-immune-system-is-involved-too\">Your immune system is involved too<\/a><\/li><li><a href=\"#sleep-also-affects-metabolism\">Sleep also affects metabolism<\/a><\/li><li><a href=\"#your-cardiovascular-system-changes-during-sleep-too\">Your cardiovascular system changes during sleep too<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 6<\/span><a class=\"ttl\" href=\"#part-6\">What else the night is working on<\/a><span class=\"cnt\"><span class=\"sec\">4 sections<\/span><span class=\"sep\"> &middot; <\/span>4 min<\/span><\/summary><ul><li><a href=\"#the-brain-may-also-be-doing-some-housekeeping\">The brain may also be doing some housekeeping<\/a><\/li><li><a href=\"#sleep-can-change-pain-sensitivity\">Sleep can change pain sensitivity<\/a><\/li><li><a href=\"#your-skin-has-a-clock-too\">Your skin has a clock too<\/a><\/li><li><a href=\"#hormones-follow-the-night-too\">Hormones follow the night too<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 7<\/span><a class=\"ttl\" href=\"#part-7\">When not enough becomes the pattern<\/a><span class=\"cnt\"><span class=\"sec\">4 sections<\/span><span class=\"sep\"> &middot; <\/span>4 min<\/span><\/summary><ul><li><a href=\"#what-happens-when-you-regularly-dont-get-enough\">What happens when you regularly don\u2019t get enough?<\/a><\/li><li><a href=\"#can-you-just-catch-up-at-the-weekend\">Can you just catch up at the weekend?<\/a><\/li><li><a href=\"#and-then-we-invented-sleep-trackers\">\u2026and then we invented sleep trackers<\/a><\/li><li><a href=\"#sometimes-the-problem-isnt-that-you-arent-trying-hard-enou\">Sometimes the problem isn\u2019t that you aren\u2019t trying hard enough<\/a><\/li><\/ul><\/details><details><summary><svg class=\"chev\" viewBox=\"0 0 12 12\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M4 2l4 4-4 4\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><span class=\"num\">PART 8<\/span><a class=\"ttl\" href=\"#part-8\">What actually helps<\/a><span class=\"cnt\"><span class=\"sec\">6 sections<\/span><span class=\"sep\"> &middot; <\/span>5 min<\/span><\/summary><ul><li><a href=\"#so-what-about-the-perfect-bedtime-routine\">So what about the perfect bedtime routine?<\/a><\/li><li><a href=\"#morning-light-is-more-important-than-it-sounds\">Morning light is more important than it sounds<\/a><\/li><li><a href=\"#sleep-is-also-about-regularity\">Sleep is also about regularity<\/a><\/li><li><a href=\"#so-should-everyone-aim-for-eight-hours\">So, should everyone aim for eight hours?<\/a><\/li><li><a href=\"#the-part-that-gets-lost-in-all-of-this\">The part that gets lost in all of this<\/a><\/li><li><a href=\"#the-surprisingly-busy-business-of-sleeping\">The surprisingly busy business of sleeping<\/a><\/li><\/ul><\/details><\/div>\n<\/div>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">01<\/div><div class=\"tx\"><p class=\"lb\">Part one of eight<\/p><h2 id=\"part-1\">The hours are not the whole story<\/h2><p class=\"sb\">How much you need varies, and the night is not one single state<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"so-how-much-sleep-do-we-actually-need\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">So, how much sleep do we actually need?<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Let\u2019s start with the number everyone wants to know.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">For most healthy adults, sleep medicine organizations recommend getting <strong class=\"eqb\">at least 7 hours<\/strong> of sleep regularly, with <strong class=\"eqb\">around 7 to 9 hours<\/strong> being a reasonable range for many adults. Eight hours sits nicely in the middle of that range, which is probably one reason it has become such a culturally familiar number.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">But there is no biological switch that flips at exactly 8 hours. Your brain does not wake up at 7 hours and 59 minutes thinking, \u201cUnfortunately, we were hoping for another minute.\u201d Sleep need varies between people, and it can change across the lifespan. Genetics, age, health, activity, environment and other factors all contribute. Some people genuinely function well with somewhat less sleep than average, while others need considerably more.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">There is also an important distinction between how much sleep you need and how much sleep you have become accustomed to getting. Humans can become surprisingly good at living with chronic sleep restriction. You may stop noticing quite how tired you are, particularly when insufficient sleep has become your normal. That does not necessarily mean your attention, reaction time, memory or emotional regulation have returned to normal.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">In other words, feeling like you\u2019ve <strong class=\"eqb\">adapted to 6 hours is not necessarily evidence that 6 hours is enough for you<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sleep-is-not-one-single-state\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sleep is not one single state<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">When we say, \u201cI slept for 8 hours,\u201d it sounds as though sleep was one continuous thing. It isn\u2019t. Throughout the night, the brain cycles through different stages of sleep, broadly divided into <em class=\"eqi\">NREM sleep<\/em>, meaning non-rapid eye movement sleep, and REM sleep, meaning rapid eye movement sleep. NREM sleep includes several stages, progressing from lighter sleep into deeper <em class=\"eqi\">slow-wave sleep<\/em>. REM is a different physiological state, characterized by relatively active brain activity, rapid eye movements and pronounced inhibition of most skeletal muscle activity.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"eq-rev\" style=\"margin-top:54px;margin-bottom:54px\"><figure class=\"slp-fig slp-hyp\"><div class=\"hd\"><p class=\"ti\">One night, four cycles<\/p><p class=\"un\">schematic<\/p><\/div><p class=\"hint\">The night runs left to right. Drag the handle at the right hand edge to end it earlier.<\/p><div class=\"sc\"><div class=\"gw\"><svg viewBox=\"0 0 860 250\" role=\"img\" aria-label=\"Across a night the sleep stages cycle repeatedly. Deep slow-wave sleep is concentrated in the first half of the night and REM periods grow longer toward morning. A handle shortens the night from the morning end.\"><defs><clipPath id=\"slphypcut\"><rect id=\"slphyprect\" x=\"0\" y=\"0\" width=\"860\" height=\"250\"\/><\/clipPath><\/defs><line x1=\"46\" y1=\"40.8\" x2=\"844\" y2=\"40.8\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><line x1=\"46\" y1=\"78.4\" x2=\"844\" y2=\"78.4\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><line x1=\"46\" y1=\"116.0\" x2=\"844\" y2=\"116.0\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><line x1=\"46\" y1=\"153.6\" x2=\"844\" y2=\"153.6\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><line x1=\"46\" y1=\"191.2\" x2=\"844\" y2=\"191.2\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"row\" x=\"37\" y=\"44.8\" text-anchor=\"end\">Awake<\/text><text class=\"row\" x=\"37\" y=\"82.4\" text-anchor=\"end\">REM<\/text><text class=\"row\" x=\"37\" y=\"120.0\" text-anchor=\"end\">N1<\/text><text class=\"row\" x=\"37\" y=\"157.6\" text-anchor=\"end\">N2<\/text><text class=\"row\" x=\"37\" y=\"195.2\" text-anchor=\"end\">N3<\/text><g 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L684.4,78.4 L684.4,116.0 L699.4,116.0 L699.4,153.6 L729.3,153.6 L729.3,78.4 L809.1,78.4 L809.1,40.8 L844.0,40.8\" fill=\"none\" stroke=\"#29538e\" stroke-width=\"2.4\" stroke-linejoin=\"round\" stroke-linecap=\"round\"\/><\/g><g clip-path=\"url(#slphypcut)\"><rect x=\"165.7\" y=\"184.2\" width=\"84.8\" height=\"14\" rx=\"4\" fill=\"#224677\"\/><rect x=\"355.2\" y=\"184.2\" width=\"59.9\" height=\"14\" rx=\"4\" fill=\"#224677\"\/><rect x=\"559.7\" y=\"184.2\" width=\"29.9\" height=\"14\" rx=\"4\" fill=\"#224677\"\/><rect x=\"280.4\" y=\"71.4\" width=\"24.9\" height=\"14\" rx=\"4\" fill=\"#a2bee5\"\/><rect x=\"450.0\" y=\"71.4\" width=\"44.9\" height=\"14\" rx=\"4\" fill=\"#a2bee5\"\/><rect x=\"619.6\" y=\"71.4\" width=\"64.8\" height=\"14\" rx=\"4\" fill=\"#a2bee5\"\/><rect x=\"729.3\" y=\"71.4\" width=\"79.8\" height=\"14\" rx=\"4\" fill=\"#a2bee5\"\/><path d=\"M46.0,40.8 L70.9,40.8 L70.9,116.0 L100.9,116.0 L100.9,153.6 L165.7,153.6 L165.7,191.2 L250.5,191.2 L250.5,153.6 L280.4,153.6 L280.4,78.4 L305.4,78.4 L305.4,153.6 L355.2,153.6 L355.2,191.2 L415.1,191.2 L415.1,153.6 L450.0,153.6 L450.0,78.4 L494.9,78.4 L494.9,40.8 L504.8,40.8 L504.8,153.6 L559.7,153.6 L559.7,191.2 L589.6,191.2 L589.6,153.6 L619.6,153.6 L619.6,78.4 L684.4,78.4 L684.4,116.0 L699.4,116.0 L699.4,153.6 L729.3,153.6 L729.3,78.4 L809.1,78.4 L809.1,40.8 L844.0,40.8\" fill=\"none\" stroke=\"#29538e\" stroke-width=\"2.4\" stroke-linejoin=\"round\" stroke-linecap=\"round\"\/><\/g><rect id=\"slphypcast\" class=\"ct\" x=\"844\" y=\"26\" width=\"0\" height=\"182\"\/><line id=\"slphypedge\" class=\"ed\" x1=\"844\" y1=\"26\" x2=\"844\" y2=\"208\" hidden\/><text class=\"ax\" x=\"46.0\" y=\"232\" text-anchor=\"middle\">11pm<\/text><text class=\"ax\" x=\"245.5\" y=\"232\" text-anchor=\"middle\">+2h<\/text><text class=\"ax\" x=\"445.0\" y=\"232\" text-anchor=\"middle\">+4h<\/text><text class=\"ax\" x=\"644.5\" y=\"232\" text-anchor=\"middle\">+6h<\/text><text class=\"ax\" x=\"844.0\" y=\"232\" text-anchor=\"middle\">7am<\/text><\/svg><div class=\"hnd\" role=\"slider\" tabindex=\"0\" hidden aria-label=\"Length of the night\" aria-valuemin=\"180\" aria-valuemax=\"480\" aria-valuenow=\"480\" aria-valuetext=\"8 hours 0 minutes, awake at 7:00am\"><i><\/i><b><\/b><\/div><\/div><\/div><div class=\"key\"><span><i style=\"background:#29538e\"><\/i>Where you are in the night<\/span><span><i style=\"background:#224677;height:10px;border-radius:3px\"><\/i>Deep sleep<\/span><span><i style=\"background:#a2bee5;height:10px;border-radius:3px\"><\/i>REM<\/span><\/div><div class=\"ro\"><p class=\"big\"><span class=\"hh\">8<\/span><span class=\"u\">h<\/span><span class=\"mm\">00<\/span><\/p><p class=\"sub\">Lights out at 11pm, awake at <b class=\"wk\">7:00am<\/b><\/p><\/div><div class=\"bars\"><p class=\"eyb\">What the night still holds<\/p><div class=\"br\"><span class=\"lb\">Deep sleep<\/span><span class=\"tr\"><i class=\"d3\"><\/i><\/span><\/div><div class=\"br\"><span class=\"lb\">REM<\/span><span class=\"tr\"><i class=\"dr\"><\/i><\/span><\/div><\/div><figcaption>These stages don\u2019t simply happen once each. They cycle throughout the night, and their proportions change as the night progresses. Earlier in the night, you generally spend more time in deep slow-wave sleep. Later in the night, REM periods become longer.<\/figcaption><p class=\"nt\">A drawn night, not a measurement. How much of each stage a real night holds, and where it falls, varies between people and between nights.<\/p><p class=\"live\" aria-live=\"polite\"><\/p><\/figure><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is one reason why sleep is more complicated than simply counting the hours. When those hours happen matters too.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">02<\/div><div class=\"tx\"><p class=\"lb\">Part two of eight<\/p><h2 id=\"part-2\">Two systems decide when you sleep<\/h2><p class=\"sb\">The circadian clock, the pressure that builds while you are awake, and what caffeine actually does to it<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"your-brain-has-an-internal-clock\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Your brain has an internal clock<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep is closely connected to your <em class=\"eqi\">circadian rhythm<\/em>, the roughly 24-hour biological timing system that helps coordinate sleep and wakefulness along with a huge number of other physiological processes. One of the major components of this system is the <em class=\"eqi\">suprachiasmatic nucleus<\/em>, a tiny group of neurons in the hypothalamus that acts as a central circadian pacemaker.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Light is one of its most important signals.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"eq-rev\" style=\"margin-top:44px;margin-bottom:46px\"><figure class=\"slp-fig\"><ol class=\"slp-path\"><li><span class=\"rail\"><\/span><span class=\"n\">Signal<\/span><span class=\"t\">Light<\/span><\/li><li><span class=\"rail\"><\/span><span class=\"n\">Sensor<\/span><span class=\"t\">The retina<\/span><\/li><li><span class=\"rail\"><\/span><span class=\"n\">Pacemaker<\/span><span class=\"t\">The suprachiasmatic nucleus<\/span><\/li><li><span class=\"rail\"><\/span><span class=\"n\">Downstream<\/span><span class=\"t\">Melatonin, alertness, temperature<\/span><\/li><\/ol><figcaption>When light reaches specialized cells in the retina, information about the light environment is sent to the brain, helping it determine where you are in the day-night cycle. This information influences the timing of melatonin secretion, alertness, body temperature and numerous other physiological processes.<\/figcaption><\/figure><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And the brain\u2019s clock isn\u2019t operating alone. There are circadian rhythms throughout the body, including in peripheral tissues and organs. Metabolism, hormone secretion, body temperature, immune activity and many other processes have their own daily patterns. This is why sleep isn\u2019t simply about becoming tired enough. <strong class=\"eqb\">Two important systems are interacting: sleep pressure and circadian timing<\/strong>.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"eq-rev\" style=\"margin-top:54px;margin-bottom:54px\"><figure class=\"slp-fig slp-2p\"><div class=\"hd\"><p class=\"ti\">Two systems, one clock<\/p><p class=\"un\">7am to 7am<\/p><\/div><svg viewBox=\"0 0 860 300\" role=\"img\" aria-label=\"Sleep pressure rises through the waking day and falls overnight, while the circadian alerting signal peaks in the evening and troughs before dawn.\"><rect x=\"567.3\" y=\"26\" width=\"274.7\" height=\"228\" fill=\"#fdf2d3\"\/><line x1=\"567.3\" y1=\"26\" x2=\"567.3\" y2=\"254\" stroke=\"#e8bf5e\" stroke-width=\"1\"\/><text class=\"ax\" x=\"557.3\" y=\"40\" text-anchor=\"end\">awake<\/text><text class=\"ax\" x=\"577.3\" y=\"40\">asleep<\/text><line x1=\"18\" y1=\"254\" x2=\"842\" y2=\"254\" stroke=\"#e2e8f0\" stroke-width=\"1.5\"\/><line x1=\"18.0\" y1=\"254\" x2=\"18.0\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"18.0\" y=\"274\" text-anchor=\"middle\">7am<\/text><line x1=\"155.3\" y1=\"254\" x2=\"155.3\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"155.3\" y=\"274\" text-anchor=\"middle\">11am<\/text><line x1=\"292.7\" y1=\"254\" x2=\"292.7\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"292.7\" y=\"274\" text-anchor=\"middle\">3pm<\/text><line x1=\"430.0\" y1=\"254\" x2=\"430.0\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"430.0\" y=\"274\" text-anchor=\"middle\">7pm<\/text><line x1=\"567.3\" y1=\"254\" x2=\"567.3\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"567.3\" y=\"274\" text-anchor=\"middle\">11pm<\/text><line x1=\"704.7\" y1=\"254\" x2=\"704.7\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"704.7\" y=\"274\" text-anchor=\"middle\">3am<\/text><line x1=\"842.0\" y1=\"254\" x2=\"842.0\" y2=\"259\" stroke=\"#e2e8f0\" stroke-width=\"1\"\/><text class=\"ax\" x=\"842.0\" y=\"274\" text-anchor=\"middle\">7am<\/text><polyline points=\"18.0,189.7 26.6,186.9 35.2,183.8 43.8,180.5 52.3,177.1 60.9,173.4 69.5,169.6 78.1,165.7 86.7,161.6 95.3,157.4 103.8,153.1 112.4,148.8 121.0,144.4 129.6,139.9 138.2,135.4 146.8,131.0 155.3,126.5 163.9,122.1 172.5,117.7 181.1,113.5 189.7,109.3 198.3,105.2 206.8,101.2 215.4,97.4 224.0,93.8 232.6,90.3 241.2,87.1 249.8,84.0 258.3,81.2 266.9,78.6 275.5,76.2 284.1,74.1 292.7,72.2 301.3,70.7 309.8,69.4 318.4,68.4 327.0,67.6 335.6,67.2 344.2,67.0 352.8,67.2 361.3,67.6 369.9,68.4 378.5,69.4 387.1,70.7 395.7,72.2 404.3,74.1 412.8,76.2 421.4,78.6 430.0,81.2 438.6,84.0 447.2,87.1 455.8,90.3 464.3,93.8 472.9,97.4 481.5,101.2 490.1,105.2 498.7,109.3 507.3,113.5 515.8,117.7 524.4,122.1 533.0,126.5 541.6,131.0 550.2,135.4 558.8,139.9 567.3,144.4 575.9,148.8 584.5,153.1 593.1,157.4 601.7,161.6 610.3,165.7 618.8,169.6 627.4,173.4 636.0,177.1 644.6,180.5 653.2,183.8 661.8,186.9 670.3,189.7 678.9,192.3 687.5,194.7 696.1,196.8 704.7,198.6 713.3,200.2 721.8,201.5 730.4,202.5 739.0,203.3 747.6,203.7 756.2,203.8 764.8,203.7 773.3,203.3 781.9,202.5 790.5,201.5 799.1,200.2 807.7,198.6 816.3,196.8 824.8,194.7 833.4,192.3 842.0,189.7\" fill=\"none\" stroke=\"#6f97cc\" stroke-width=\"2.6\" stroke-linecap=\"round\" stroke-dasharray=\"8 7\"\/><polyline points=\"18.0,217.5 26.6,211.8 35.2,206.2 43.8,200.8 52.3,195.6 60.9,190.6 69.5,185.8 78.1,181.1 86.7,176.6 95.3,172.2 103.8,168.0 112.4,164.0 121.0,160.0 129.6,156.2 138.2,152.6 146.8,149.0 155.3,145.6 163.9,142.3 172.5,139.1 181.1,136.0 189.7,133.1 198.3,130.2 206.8,127.4 215.4,124.7 224.0,122.1 232.6,119.6 241.2,117.2 249.8,114.9 258.3,112.6 266.9,110.4 275.5,108.3 284.1,106.3 292.7,104.3 301.3,102.4 309.8,100.6 318.4,98.8 327.0,97.1 335.6,95.5 344.2,93.9 352.8,92.4 361.3,90.9 369.9,89.4 378.5,88.0 387.1,86.7 395.7,85.4 404.3,84.2 412.8,83.0 421.4,81.8 430.0,80.7 438.6,79.6 447.2,78.5 455.8,77.5 464.3,76.5 472.9,75.6 481.5,74.7 490.1,73.8 498.7,72.9 507.3,72.1 515.8,71.3 524.4,70.6 533.0,69.8 541.6,69.1 550.2,68.4 558.8,67.7 567.3,67.1 575.9,78.7 584.5,89.5 593.1,99.4 601.7,108.6 610.3,117.0 618.8,124.8 627.4,132.0 636.0,138.6 644.6,144.7 653.2,150.4 661.8,155.6 670.3,160.4 678.9,164.8 687.5,168.9 696.1,172.6 704.7,176.1 713.3,179.3 721.8,182.3 730.4,185.0 739.0,187.5 747.6,189.9 756.2,192.0 764.8,194.0 773.3,195.8 781.9,197.5 790.5,199.0 799.1,200.5 807.7,201.8 816.3,203.0 824.8,204.1 833.4,205.2 842.0,217.5\" fill=\"none\" stroke=\"#29538e\" stroke-width=\"3.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/><\/svg><div class=\"key\"><span><i style=\"background:#29538e\"><\/i>Sleep pressure<\/span><span><i style=\"background:#6f97cc\"><\/i>Circadian alerting signal<\/span><span><i style=\"background:#fdf2d3;height:10px;border-radius:3px;border:1px solid #e8bf5e\"><\/i>Asleep<\/span><\/div><figcaption>Sleep pressure builds the longer you\u2019re awake. Circadian timing helps determine when your body is biologically inclined to be awake or asleep. Ideally, these systems line up. When they don\u2019t, you can end up in the slightly ridiculous situation of being absolutely exhausted but somehow wide awake at 1 a.m.<\/figcaption><\/figure><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"why-does-sleep-pressure-build\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Why does sleep pressure build?<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">One of the molecules involved in sleep pressure is <span class=\"eq-term\" tabindex=\"0\" aria-describedby=\"gd-1\"><em class=\"eqi\">adenosine<\/em><span class=\"eq-def\" role=\"tooltip\" id=\"gd-1\"><b>adenosine<\/b>A small molecule that accumulates in the brain across the hours you are awake. Its build-up is one of the signals the brain uses to register how long you have been awake.<\/span><\/span>. During wakefulness, adenosine gradually accumulates in the brain and contributes to the feeling of sleepiness. During sleep, that pressure decreases. This is part of the reason caffeine can make you feel more alert. Caffeine primarily works by blocking adenosine receptors, reducing the brain\u2019s ability to detect some of that sleep pressure. It doesn\u2019t actually remove the underlying need for sleep. <strong class=\"eqb\">It makes the sleepiness less noticeable<\/strong>.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Which is useful when you need to function, but it is also why caffeine can sometimes give us a slightly misleading impression that the problem has been solved. You haven\u2019t necessarily become less sleep deprived. You may simply feel less of it.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"and-then-you-fall-asleep\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">And then you fall asleep<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">As you move from wakefulness into NREM sleep, brain activity changes substantially. In deeper NREM sleep, particularly slow-wave sleep, large groups of neurons begin to show highly synchronized patterns of activity. On an EEG, this appears as the large, slow oscillations that give slow-wave sleep its name. This is one of the most fascinating parts of sleep because the sleeping brain is doing some very specific work with information.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">During the day, you encounter an enormous amount of information. Most of it is irrelevant. Some of it matters. Some of it matters a lot. Your brain has to figure out what to keep, what to integrate with existing knowledge, what to strengthen and what can safely fade into the background. Sleep appears to be an important part of that process.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">03<\/div><div class=\"tx\"><p class=\"lb\">Part three of eight<\/p><h2 id=\"part-3\">Your brain is working on the day<\/h2><p class=\"sb\">Memory consolidation, why all-nighters cost more than they buy, and what REM is still not explaining<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"your-brain-does-not-simply-store-memories\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Your brain does not simply \u201cstore\u201d memories<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">We often talk about memory as if the brain were a computer with a folder called <span class=\"fold\"><svg viewBox=\"0 0 16 13\" aria-hidden=\"true\" focusable=\"false\"><path d=\"M1 3.2a1.2 1.2 0 0 1 1.2-1.2h3.4l1.5 1.7h6.7a1.2 1.2 0 0 1 1.2 1.2v6.4a1.2 1.2 0 0 1-1.2 1.2H2.2A1.2 1.2 0 0 1 1 11.3z\"\/><\/svg><span>IMPORTANT THINGS TO REMEMBER<\/span><\/span>. It is much more complicated than that. When you learn something new, the initial memory trace is relatively fragile. During subsequent sleep, neural patterns associated with recent experiences can be reactivated and interacted with other brain systems.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This process, broadly referred to as <em class=\"eqi\">memory consolidation<\/em>, can make memories more stable and can help integrate newly learned information with what you already know. NREM sleep, particularly slow-wave sleep and <span class=\"eq-term\" tabindex=\"0\" aria-describedby=\"gd-2\"><em class=\"eqi\">sleep spindles<\/em><span class=\"eq-def\" role=\"tooltip\" id=\"gd-2\"><b>sleep spindles<\/b>Short bursts of fast, rhythmic brain activity, roughly a second long, that appear on an EEG during lighter NREM sleep.<\/span><\/span>, appears to play an important role in several aspects of memory consolidation. REM sleep is also involved in learning and memory, although the old idea that NREM is simply for facts and REM is simply for emotions or dreams is far too neat.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Different types of memory appear to interact with different aspects of sleep, and the processes are overlapping rather than neatly separated.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is one reason sleep is so important for learning. The work isn\u2019t finished when you close the textbook.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"this-is-why-all-nighters-are-such-a-questionable-strategy\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">This is why all-nighters are such a questionable strategy<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Imagine spending an entire night studying before an exam. On paper, it looks productive. You have gained several additional hours of exposure to the material. But those hours have come at the expense of sleep, which is itself involved in learning, memory consolidation, attention and executive function. So there is a slightly unfortunate trade-off happening.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">You are giving yourself more time to put information into your brain while simultaneously reducing some of the processes that help you use that information effectively. This doesn\u2019t mean that staying up late before an exam guarantees failure. Human beings are resilient, and sometimes life genuinely requires us to get through a bad night.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">It does mean that, when learning is the goal, sleep is not simply the thing you do after the important work is finished. <strong class=\"eqb\">Sleep is part of the learning process<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"and-then-there-is-rem-sleep\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">And then there is REM sleep<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\"><em class=\"eqi\">REM sleep<\/em> is the stage most strongly associated with vivid dreaming, although dreaming can occur during NREM sleep too. During REM, some aspects of brain activity look surprisingly similar to wakefulness. At the same time, most skeletal muscles are strongly inhibited, which is one of the mechanisms that prevents us from physically acting out most of our dreams.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">The brain is active, but the body is largely prevented from following along. REM sleep has been linked to memory processing, emotional processing and aspects of learning, although the exact functions of REM are still being worked out. This is important because sleep science is full of things that are well established, things that are strongly supported but still being refined, and things that are genuinely unresolved.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#fdf3da;border-color:#f2e2b8;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WORTH BEING CLEAR ABOUT<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Dreaming is a good example. We know a lot about when dreaming happens and what brain systems are involved. We still don\u2019t have one universally accepted answer to the much bigger question of why subjective dreams exist at all. There are several interesting theories, involving memory, emotion, threat simulation, predictive processing and spontaneous neural activity, but none can currently be presented as the definitive explanation.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Science is allowed to say, \u201cWe\u2019re not sure yet.\u201d<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">04<\/div><div class=\"tx\"><p class=\"lb\">Part four of eight<\/p><h2 id=\"part-4\">A bad night changes the next day<\/h2><p class=\"sb\">More reactive emotions, more regulatory effort, and the loop between stress and sleep<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sleep-changes-the-way-you-process-emotions\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sleep changes the way you process emotions<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">There is another reason a bad night\u2019s sleep can make the next day feel strangely different. Sleep deprivation affects emotional processing.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Experimental research has found that insufficient sleep can increase emotional reactivity and alter communication between brain regions involved in generating emotional responses and regions involved in regulating them. The <span class=\"eq-term\" tabindex=\"0\" aria-describedby=\"gd-3\"><em class=\"eqi\">amygdala<\/em><span class=\"eq-def\" role=\"tooltip\" id=\"gd-3\"><b>amygdala<\/b>A pair of small structures deep in the brain that help pick out what is emotionally significant and set a response going. It works as part of a network rather than as a fear center on its own.<\/span><\/span>, for example, can become more reactive to emotional stimuli following sleep deprivation, while communication with regulatory prefrontal regions can be altered.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This doesn\u2019t mean that sleep deprivation makes you irrational. It means that <strong class=\"eqb\">the same emotional experience can require more regulatory effort when you are tired<\/strong>.<\/p>\n\n\n\n<div style=\"margin-top:0;margin-bottom:30px\"><ul class=\"slp-run\"><li>Something mildly annoying may feel much more irritating.<\/li><li>A difficult conversation may feel harder to navigate.<\/li><li>A small problem may seem disproportionately important.<\/li><\/ul><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">You may have less patience, less flexibility and less ability to pause before reacting. And after a good night\u2019s sleep, the exact same situation can sometimes feel noticeably more manageable. Sleep hasn\u2019t necessarily changed the problem. It may have changed the brain you are bringing to the problem.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sleep-and-stress-have-a-complicated-relationship\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sleep and stress have a complicated relationship<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Stress can interfere with sleep, and poor sleep can make the stress system harder to regulate. The hypothalamic-pituitary-adrenal axis, usually shortened to the <em class=\"eqi\">HPA axis<\/em>, is <a href=\"\/your-brain-on-stress\/\" style=\"color:#29538e;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:2px;text-decoration-color:#29538e\">one of the body\u2019s major systems for responding to stress<\/a>. Cortisol, one of its best-known hormones, follows a strong circadian pattern. Healthy sleep and circadian rhythms help organize that pattern.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep disruption can affect stress-system responsiveness, and research suggests that poor sleep can increase or potentiate some physiological responses to stress.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This creates a rather unpleasant feedback loop.<\/p>\n\n\n\n<div style=\"margin-top:0;margin-bottom:30px\"><ul class=\"slp-run loop\"><li>You are stressed, so you don\u2019t sleep well.<\/li><li>You don\u2019t sleep well, so your nervous system is more reactive the next day.<\/li><li>You feel more overwhelmed.<\/li><li>Then you have another difficult night.<\/li><\/ul><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is one reason persistent sleep problems deserve more attention than simply being told to \u201crelax.\u201d<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">05<\/div><div class=\"tx\"><p class=\"lb\">Part five of eight<\/p><h2 id=\"part-5\">Your body is not resting either<\/h2><p class=\"sb\">Immune signaling, glucose and appetite, and a cardiovascular system working under different conditions<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"your-immune-system-is-involved-too\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Your immune system is involved too<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Your immune system doesn\u2019t simply clock off because you have gone to bed. Sleep and immune function are closely connected in both directions.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep influences immune signaling, including the activity of various <span class=\"eq-term\" tabindex=\"0\" aria-describedby=\"gd-4\"><em class=\"eqi\">cytokines<\/em><span class=\"eq-def\" role=\"tooltip\" id=\"gd-4\"><b>cytokines<\/b>Small signaling proteins that immune cells use to communicate with each other and with the rest of the body. Some raise inflammation and some settle it down.<\/span><\/span> and immune cells. At the same time, immune activation can change sleep.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Think about what happens when you\u2019re ill. You often become sleepy, sluggish and much more interested in lying down. That is not necessarily your body being inefficient. Sleep is part of the physiological response to illness, and changes in sleep may help support immune processes. Chronic sleep disruption, meanwhile, has been associated with alterations in inflammatory and immune signaling.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">The relationship is complicated, and inflammation is not simply \u201cbad\u201d or something we should eliminate. Immune signaling is essential for normal physiology. But the broader point is fairly straightforward: <strong class=\"eqb\">Sleep and immune function are in constant conversation<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sleep-also-affects-metabolism\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sleep also affects metabolism<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is where sleep starts becoming relevant to almost every part of health. Sleep restriction can affect glucose regulation, insulin sensitivity, appetite, eating behavior and autonomic nervous system activity.<\/p>\n\n\n\n<div style=\"margin-top:34px;margin-bottom:36px\"><div class=\"slp-pair\"><div class=\"side cream\"><p class=\"q\">The relationship between sleep and weight is often presented online as though there are two simple hormones, one that makes you hungry and one that makes you full, and sleep controls both like a little hormonal remote control.<\/p><p class=\"nt\">Reality is more complicated.<\/p><\/div><div class=\"rule\" aria-hidden=\"true\"><\/div><div class=\"side mist\"><p class=\"q\">Sleep is therefore one piece of metabolic health, not a magical weight-management intervention.<\/p><\/div><\/div><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\"><em class=\"eqi\">Leptin and ghrelin<\/em> are involved in appetite regulation, but human studies don\u2019t always produce the clean pattern that popular explanations suggest. Sleep loss can affect appetite through several overlapping mechanisms, including <a href=\"\/dopamine-addiction-everyday-habits\/\" style=\"color:#29538e;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1.5px;text-decoration-color:#d4e1f2\">changes in reward processing<\/a>, food choices, glucose metabolism and hormonal regulation. Over time, habitual insufficient sleep is associated with increased risk of <strong class=\"eqb\">obesity and type 2 diabetes<\/strong>, although the relationship is bidirectional and influenced by many other factors.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"your-cardiovascular-system-changes-during-sleep-too\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Your cardiovascular system changes during sleep too<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">During healthy NREM sleep, heart rate and blood pressure generally decrease compared with wakefulness. The autonomic nervous system shifts its balance, and cardiovascular demand changes. Again, this is not the same as the cardiovascular system simply \u201cresting.\u201d It is operating under a different set of conditions. Habitually short or disrupted sleep has been associated with increased cardiovascular risk, including hypertension, coronary heart disease and stroke.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#fdf3da;border-color:#f2e2b8;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WORTH BEING CLEAR ABOUT<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">There is an important scientific caveat here. Association does not automatically mean that poor sleep directly causes every cardiovascular outcome observed in population studies. Sleep problems can coexist with obesity, depression, sleep apnoea, chronic stress, shift work and other health conditions that themselves affect cardiovascular risk.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Still, the evidence is strong enough that sleep is increasingly considered an important part of cardiovascular health rather than a separate lifestyle issue.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">06<\/div><div class=\"tx\"><p class=\"lb\">Part six of eight<\/p><h2 id=\"part-6\">What else the night is working on<\/h2><p class=\"sb\">Waste clearance, pain, skin and hormones, and where the popular version runs ahead of the evidence<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"the-brain-may-also-be-doing-some-housekeeping\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">The brain may also be doing some housekeeping<\/h3>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-66cb9a2b wp-block-group-is-layout-constrained\" style=\"border-left-color:#d4e1f2;border-left-width:4px;border-left-style:solid;border-radius:0px;margin-top:30px;margin-bottom:30px;padding:2px 0px 2px 26px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#5a6b7d;margin-top:0;margin-bottom:8px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.227), 16px);line-height:1.5\">You may have heard the phrase:<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#29538e;margin-top:0;margin-bottom:0;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.625), 19.5px);font-weight:600;line-height:1.5\">\u201cYour brain cleans itself while you sleep.\u201d<\/p>\n\n\n<\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">It\u2019s a very appealing explanation. There is a real scientific story underneath it, involving the <span class=\"eq-term\" tabindex=\"0\" aria-describedby=\"gd-5\"><em class=\"eqi\">glymphatic system<\/em><span class=\"eq-def\" role=\"tooltip\" id=\"gd-5\"><b>glymphatic system<\/b>A proposed route by which cerebrospinal fluid moves through brain tissue and carries waste products away. Much of the direct evidence so far comes from animal studies.<\/span><\/span> and the movement of cerebrospinal fluid through the brain. Animal research has suggested that certain forms of fluid movement and waste clearance increase during sleep. This has led to considerable interest in whether sleep helps the brain manage metabolic waste and maintain its internal environment. Human research is much less settled.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">There is evidence connecting sleep with cerebrospinal fluid dynamics and processes potentially involved in waste clearance, but the exact mechanisms, magnitude and clinical importance in humans are still being investigated.<\/p>\n\n\n\n<div style=\"margin-top:34px;margin-bottom:36px\"><div class=\"slp-pair\"><div class=\"side mist\"><p class=\"q\">So it is reasonable to say that sleep appears to support important aspects of brain homeostasis.<\/p><p class=\"nt\">The first statement is interesting science.<\/p><\/div><div class=\"rule\" aria-hidden=\"true\"><\/div><div class=\"side cream\"><p class=\"q\">It is much less reasonable to say that eight hours of sleep literally \u201cflushes toxins out of your brain.\u201d<\/p><p class=\"nt\">The second is a little too tidy.<\/p><\/div><\/div><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sleep-can-change-pain-sensitivity\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sleep can change pain sensitivity<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep and pain have a particularly interesting relationship because the relationship goes both ways. Pain can make it difficult to sleep. But poor sleep can also increase sensitivity to pain.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Experimental studies have found that sleep deprivation can <strong class=\"eqb\">increase sensitivity to painful stimuli<\/strong>, and research in people with <strong class=\"eqb\">chronic pain<\/strong> consistently finds a relationship between sleep disturbance and greater pain burden.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This makes sense when we remember that pain is not simply a direct readout of tissue damage. Pain is an experience produced by the nervous system after it integrates information from the body, the environment and the brain\u2019s predictions and expectations. Sleep influences that nervous system. So after a poor night\u2019s sleep, your tissues have not necessarily become more damaged.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Your brain may simply be processing incoming sensory information differently. This is one of the reasons sleep can become particularly important for people dealing with persistent pain.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"your-skin-has-a-clock-too\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Your skin has a clock too<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">The skin is also influenced by circadian biology. Processes including barrier function, blood flow, temperature regulation, cell proliferation and aspects of repair show daily variation. There is growing evidence that sleep disruption can affect skin barrier function, inflammation and aspects of skin aging, although this area is not nearly as well established as the research linking sleep to cognition or cardiovascular health.<\/p>\n\n\n\n<div style=\"margin-top:34px;margin-bottom:36px\"><div class=\"slp-pair\"><div class=\"side cream\"><p class=\"q\">So no, sleeping eight hours will not magically give you perfect skin.<\/p><\/div><div class=\"rule\" aria-hidden=\"true\"><\/div><div class=\"side mist\"><p class=\"q\">But it would also be wrong to think that sleep has nothing to do with skin biology.<\/p><\/div><\/div><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Your skin is part of your body. It is therefore not particularly surprising that it responds to the same biological rhythms affecting the rest of you.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"hormones-follow-the-night-too\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Hormones follow the night too<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep is closely intertwined with endocrine function. <strong class=\"eqb\">Growth hormone<\/strong> secretion is strongly associated with slow-wave sleep. <strong class=\"eqb\">Cortisol<\/strong> follows a circadian rhythm. <strong class=\"eqb\">Melatonin<\/strong> rises in response to darkness and helps signal biological night. <a href=\"\/is-it-your-hormones\/\" style=\"color:#29538e;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1.5px;text-decoration-color:#d4e1f2\">Other hormones<\/a> are influenced by the interaction between sleep, circadian timing, food intake and wakefulness. This is another reason why sleep timing matters.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Two people could technically spend the same number of hours asleep while having very different sleep schedules, and those schedules can interact differently with their circadian systems. Sleep health therefore isn\u2019t only about duration. <strong class=\"eqb\">It includes duration, timing, regularity, continuity and quality<\/strong>.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#fdf3da;border-color:#f2e2b8;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">A SMALL REMINDER ABOUT SLEEP SCIENCE<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep research is full of things we know very well, things we have pretty good evidence for, and things that are genuinely still being worked out. We know that insufficient sleep affects attention, mood, learning and several aspects of physical health. We have strong evidence for the importance of sleep duration, and increasingly good evidence that timing and regularity matter too.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Other areas are more tentative. The exact role of dreaming is still debated. The human glymphatic story is fascinating but nowhere near as settled as social media sometimes makes it sound. And there isn\u2019t one single explanation for why we sleep in the first place. That isn\u2019t a weakness of sleep science. It\u2019s actually one of the interesting things about it. The more we learn, the clearer it becomes that sleep is not one simple biological function waiting to be explained.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">07<\/div><div class=\"tx\"><p class=\"lb\">Part seven of eight<\/p><h2 id=\"part-7\">When not enough becomes the pattern<\/h2><p class=\"sb\">One bad night is not the problem, trackers are not sleep laboratories, and some of this is not insomnia at all<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"what-happens-when-you-regularly-dont-get-enough\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">What happens when you regularly don\u2019t get enough?<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">One short night is not a catastrophe. Really. You can have a terrible night of sleep because of travel, stress, an exam, a baby, illness, a noisy neighbor or absolutely no identifiable reason whatsoever. The body is remarkably good at recovering from occasional disruption. The bigger concern is what happens when insufficient or disrupted sleep becomes the pattern.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Habitual sleep restriction has been associated with impaired attention, slower reaction times, poorer executive function, metabolic changes, cardiovascular risk and poorer mental health outcomes.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And one of the stranger things about chronic sleep restriction is that subjective awareness doesn\u2019t always keep up with objective impairment. You may feel as though you are functioning normally because you have become accustomed to your baseline. That is very different from proving that your baseline is optimal.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"can-you-just-catch-up-at-the-weekend\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Can you just catch up at the weekend?<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Extra sleep after a period of sleep restriction is absolutely useful. If you have been sleeping too little, allowing yourself to sleep longer can help recovery. But weekend catch-up sleep is not necessarily equivalent to consistently getting enough sleep throughout the week. Different physiological effects recover at different rates, and research is still investigating exactly how completely various consequences of chronic sleep restriction reverse once normal sleep is restored. So if your schedule looks like:<\/p>\n\n\n\n<div style=\"margin-top:0;margin-bottom:30px\"><ul class=\"slp-pill\"><li>Monday to Friday: survive<\/li><li>Saturday + Sunday: hibernate<\/li><\/ul><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">then your body may appreciate the weekend sleep, but it would probably prefer a little more consistency throughout the week. Sleep isn\u2019t really designed as a weekly accounting system.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"and-then-we-invented-sleep-trackers\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">\u2026and then we invented sleep trackers<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is where modern sleep gets slightly funny. We now have watches and rings that can estimate how long we slept, how much REM we supposedly got, how much deep sleep we supposedly got and whether our recovery score is apparently acceptable. Some of these devices are genuinely useful. They can help identify patterns. But <strong class=\"eqb\">they are not little sleep laboratories<\/strong>.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-f86ed65e wp-block-group-is-layout-constrained\" style=\"background-color:#eef3fa;border-color:#d4e1f2;border-width:1.5px;border-style:solid;border-radius:20px;margin-top:46px;margin-bottom:46px;padding:34px 38px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#224677;margin-top:0;margin-bottom:12px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WHAT THE RESEARCH SUPPORTS<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:0;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Clinical sleep studies use techniques such as <strong class=\"eqb\">EEG<\/strong>, <strong class=\"eqb\">electrooculography<\/strong> and <strong class=\"eqb\">electromyography<\/strong> to distinguish sleep stages and assess physiological events. Consumer wearables infer sleep from movement, heart rate and other signals. They can be reasonably useful for estimating sleep duration and identifying broad trends, but their ability to accurately distinguish sleep stages is much more limited.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And there is another issue that gets discussed less often. If your sleep tracker tells you that your REM sleep was 14% instead of 19%, you might spend the entire morning worrying about whether your brain is functioning properly. The worrying itself is not particularly helpful. Sleep is one of those biological processes that can become harder when you start treating it like a performance you have to get exactly right.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">There is even a term, <em class=\"eqi\">orthosomnia<\/em>, used to describe an unhealthy preoccupation with achieving supposedly perfect sleep metrics. The irony is almost too good. You can become so worried about sleeping correctly that you make sleep more difficult.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sometimes-the-problem-isnt-that-you-arent-trying-hard-enou\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sometimes the problem isn\u2019t that you aren\u2019t trying hard enough<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is particularly important with chronic insomnia. If someone has been lying awake for hours every night for months, \u201cjust practice better sleep hygiene\u201d is not necessarily an adequate answer. <strong class=\"eqb\">Insomnia can become self-perpetuating<\/strong>.<\/p>\n\n\n\n<div style=\"margin-top:0;margin-bottom:30px\"><ul class=\"slp-run loop\"><li>You go to bed expecting not to sleep.<\/li><li>You start monitoring the clock.<\/li><li>You calculate how many hours you have left.<\/li><li>You become frustrated.<\/li><li>You worry about how terrible tomorrow will be.<\/li><li>Your physiological arousal increases.<\/li><\/ul><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And now the bed has become associated not only with sleep, but with vigilance and frustration. This is one reason cognitive behavioral therapy for insomnia, or CBT-I, is considered a first-line treatment for chronic insomnia. It addresses the behavioral and cognitive processes that can maintain insomnia rather than simply telling someone to try harder to relax.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And sometimes persistent sleepiness isn\u2019t insomnia at all. Sleep apnoea, restless legs syndrome, circadian rhythm disorders, medications, depression, anxiety, pain and numerous medical conditions can all affect sleep or daytime alertness. If someone is consistently sleeping enough but remains profoundly sleepy or unrefreshed, that is worth investigating rather than simply buying another supplement.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div style=\"margin-top:92px;margin-bottom:34px\"><div class=\"slp-part\"><div class=\"no\">08<\/div><div class=\"tx\"><p class=\"lb\">Part eight of eight<\/p><h2 id=\"part-8\">What actually helps<\/h2><p class=\"sb\">Light, regularity, and why sleep does not need to become another project<\/p><\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d12c95ff wp-block-group-is-layout-constrained\">\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"so-what-about-the-perfect-bedtime-routine\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">So what about the perfect bedtime routine?<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">The internet has made sleep sound like an elaborate ritual.<\/p>\n\n\n\n<div style=\"margin-top:0;margin-bottom:30px\"><ul class=\"slp-pill\"><li>Blue-light-blocking glasses<\/li><li>Magnesium<\/li><li>Special teas<\/li><li>Cold rooms<\/li><li>Hot baths<\/li><li>Mouth tape<\/li><li>Red lights<\/li><li>Sleep supplements<\/li><li>Breathing exercises<\/li><li>Weighted blankets<\/li><li>Sleep trackers<\/li><\/ul><\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Some of these things can be useful for particular people. None of them replaces the fundamentals. For most adults, the biggest pieces are surprisingly unglamorous: <strong class=\"eqb\">enough opportunity for sleep<\/strong>, <strong class=\"eqb\">a reasonably consistent schedule<\/strong>, <strong class=\"eqb\">appropriate exposure to light<\/strong>, <strong class=\"eqb\">regular physical activity<\/strong>, <strong class=\"eqb\">a sleep environment that works for you<\/strong>, and <strong class=\"eqb\">addressing substances or medications that interfere with sleep<\/strong>.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">If you have chronic insomnia, evidence-based behavioral treatment matters much more than assembling the world\u2019s most impressive collection of bedtime products. And if you have a sleep disorder, treating the disorder matters more than perfecting your evening routine.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"morning-light-is-more-important-than-it-sounds\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Morning light is more important than it sounds<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">One particularly useful piece of the puzzle is light. Your circadian system uses environmental light to help determine where you are in the day. Getting bright light, particularly outdoor light, earlier in the day can help anchor circadian timing. In the evening, reducing exposure to bright light can support the biological transition toward night.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This doesn\u2019t mean you need to live in darkness after sunset. It means your brain benefits from receiving reasonably clear information about daytime being daytime and nighttime being nighttime. Modern life is unusually good at confusing those signals. We can sit under bright artificial lights at midnight and then spend the following morning indoors with very little daylight.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">From the perspective of our ancient circadian machinery, this is a slightly strange arrangement.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"sleep-is-also-about-regularity\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">Sleep is also about regularity<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">There is a tendency to focus entirely on duration.<\/p>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-66cb9a2b wp-block-group-is-layout-constrained\" style=\"border-left-color:#d4e1f2;border-left-width:4px;border-left-style:solid;border-radius:0px;margin-top:30px;margin-bottom:30px;padding:2px 0px 2px 26px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#29538e;margin-top:0;margin-bottom:0;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.625), 19.5px);font-weight:600;line-height:1.5\">\u201cHow many hours did you get?\u201d<\/p>\n\n\n<\/div>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">But sleep regularity appears to matter too. Going to bed and waking at roughly similar times gives your circadian system more predictable signals. This doesn\u2019t mean you have to wake up at exactly 6:47 a.m. every single day or that sleeping an extra hour on Sunday is biologically dangerous. It means that a reasonably stable pattern is generally easier for the body to organize than constantly shifting between very different schedules.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">This is particularly obvious with <em class=\"eqi\">social jet lag<\/em>, where sleep timing changes substantially between workdays and free days. You can be technically getting enough sleep while still repeatedly shifting your biological clock.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"so-should-everyone-aim-for-eight-hours\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">So, should everyone aim for eight hours?<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Eight hours is a perfectly reasonable target if it works for you. It is also completely fine if your natural sleep need turns out to be closer to 7 or 9 hours. The point isn\u2019t to hit a magical number. The point is to get enough sleep, regularly enough, at a time that works reasonably well with your biology.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And if you\u2019re consistently exhausted despite giving yourself enough time to sleep, that is more interesting than whether your average happens to be 7 hours and 52 minutes. Your body is giving you information. It is worth listening to.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"the-part-that-gets-lost-in-all-of-this\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">The part that gets lost in all of this<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">Sleep has somehow acquired two opposite reputations. On one side, it is treated as wasted time. Something you can sacrifice when life gets busy. On the other, it has become another thing to optimize obsessively, complete with scores, supplements, routines and increasingly complicated rules about what constitutes \u201cgood\u201d sleep. Neither is particularly helpful. <strong class=\"eqb\">Sleep is not wasted time<\/strong>.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">But it also does not need to become another project. You don\u2019t need to achieve perfect sleep. You need to give your body a reasonable opportunity to sleep enough, most of the time. You need to pay attention if something is persistently getting in the way. And you need to remember that one bad night does not undo your health.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"the-surprisingly-busy-business-of-sleeping\" style=\"color:#29538e;margin-top:80px;margin-bottom:20px;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-style:normal;font-weight:700;line-height:1.28\">The surprisingly busy business of sleeping<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">From the outside, sleep looks like inactivity. Inside, it is an extraordinarily organized biological state. Your brain changes its patterns of activity. Memories are processed. Neural connections are adjusted. Hormones follow different rhythms. The autonomic nervous system changes its balance. Immune signaling shifts. Metabolism changes. Emotional processing is influenced. Pain sensitivity can change. The brain\u2019s internal environment is maintained in ways we are still trying to understand.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#2b302f;margin-top:0;margin-bottom:26px;font-size:clamp(14.082px, 0.88rem + ((1vw - 3.2px) * 0.786), 21px);line-height:1.68\">And you don\u2019t consciously experience most of it. That is probably part of why sleep is so easy to underestimate. When you\u2019re awake, you can see what you\u2019re accomplishing. When you\u2019re asleep, you can\u2019t. But some of the most important things your brain does are happening precisely when you are not paying attention to them.<\/p>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background eq-ondark has-global-padding is-layout-constrained wp-container-core-group-is-layout-e27886f6 wp-block-group-is-layout-constrained\" style=\"background-color:#17273d;border-radius:22px;margin-top:56px;margin-bottom:44px;padding:46px 50px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#a8c4e6;margin-top:0;margin-bottom:8px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.341), 17px);line-height:1.6\">So maybe sleep isn\u2019t the time when your brain stops working.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#a8c4e6;margin-top:0;margin-bottom:18px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.341), 17px);line-height:1.6\">Maybe it is the time when, finally, it gets to work on some of the things it cannot do quite as well while you\u2019re busy being awake.<\/p>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#ffffff;margin-top:0;margin-bottom:0;font-size:clamp(16.293px, 1.018rem + ((1vw - 3.2px) * 0.989), 25px);font-weight:600;line-height:1.5\">And that makes those eight hours look a little less like lost time.<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"wp-block-group has-background has-global-padding is-layout-constrained wp-container-core-group-is-layout-69c879e7 wp-block-group-is-layout-constrained\" style=\"background-color:#f7fafb;border-color:#e2e8f0;border-width:1.5px;border-style:solid;border-radius:18px;margin-top:0;margin-bottom:44px;padding:30px 34px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#5a6b7d;margin-top:0;margin-bottom:14px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">REFERENCES<\/p>\n\n\n\n<ol class=\"wp-block-list has-text-color has-work-sans-regular-font-family\" style=\"color:#4b5560;margin-top:0;margin-bottom:12px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.17), 15.5px);line-height:1.7\">\n<li><a href=\"https:\/\/doi.org\/10.5665\/sleep.4716\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Watson, N. F., Badr, M. S., Belenky, G., et al. (2015). Recommended amount of sleep for a healthy adult: A joint consensus recommendation of the American Academy of Sleep Medicine and Sleep Research Society. Sleep, 38(6), 843-844.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1161\/CIR.0000000000000444\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">St-Onge, M. P., Grandner, M. A., Brown, D., et al. (2016). Sleep duration and quality: Impact on lifestyle behaviors and cardiometabolic health. Circulation, 134(18), e367-e386.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.2147\/NSS.S134864\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Medic, G., Wille, M., &amp; Hemels, M. E. H. (2017). Short- and long-term health consequences of sleep disruption. Nature and Science of Sleep, 9, 151-161.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.sleep.2016.08.006\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Itani, O., Jike, M., Watanabe, N., &amp; Kaneita, Y. (2017). Short sleep duration and health outcomes: A systematic review, meta-analysis, and meta-regression. Sleep Medicine, 32, 246-256.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1155\/2017\/1364387\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Dolezal, B. A., Neufeld, E. V., Boland, D. M., Martin, J. L., &amp; Cooper, C. B. (2017). Interrelationship between sleep and exercise: A systematic review. Advances in Preventive Medicine, 2017, 1364387.<\/a><\/li>\n\n\n\n<li>Borb\u00e9ly, A. A. (1982). A two process model of sleep regulation. Human Neurobiology, 1(3), 195-204.<\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1523\/JNEUROSCI.15-05-03526.1995\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Dijk, D. J., &amp; Czeisler, C. A. (1995). Contribution of the circadian pacemaker and the sleep homeostat to sleep propensity, sleep structure, electroencephalographic slow waves, and sleep spindle activity in humans. Journal of Neuroscience, 15(5), 3526-3538.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1126\/science.284.5423.2177\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Czeisler, C. A., Duffy, J. F., Shanahan, T. L., et al. (1999). Stability, precision, and near-24-hour period of the human circadian pacemaker. Science, 284(5423), 2177-2181.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1139\/apnm-2020-0032\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Chaput, J. P., Dutil, C., Featherstone, R., et al. (2020). Sleep timing, sleep consistency, and health in adults: A systematic review. Applied Physiology, Nutrition, and Metabolism, 45(10 Suppl 2), S232-S247.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1152\/physrev.00032.2012\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Rasch, B., &amp; Born, J. (2013). About sleep\u2019s role in memory. Physiological Reviews, 93(2), 681-766.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1038\/s41593-019-0467-3\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Klinzing, J. G., Niethard, N., &amp; Born, J. (2019). Mechanisms of systems memory consolidation during sleep. Nature Neuroscience, 22, 1598-1610.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1038\/nrn2762\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Diekelmann, S., &amp; Born, J. (2010). The memory function of sleep. Nature Reviews Neuroscience, 11, 114-126.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.5665\/sleep.3572\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Cairney, S. A., Durrant, S. J., Hulleman, J., &amp; Lewis, P. A. (2014). Targeted memory reactivation during slow wave sleep facilitates emotional memory consolidation. Sleep, 37(4), 701-707.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1037\/a0016570\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Walker, M. P., &amp; van der Helm, E. (2009). Overnight therapy? The role of sleep in emotional brain processing. Psychological Bulletin, 135(5), 731-748.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.cub.2007.08.007\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Yoo, S. S., Gujar, N., Hu, P., Jolesz, F. A., &amp; Walker, M. P. (2007). The human emotional brain without sleep: A prefrontal amygdala disconnect. Current Biology, 17(20), R877-R878.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.smrv.2015.12.006\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Palmer, C. A., &amp; Alfano, C. A. (2017). Sleep and emotion regulation: An organizing, integrative review. Sleep Medicine Reviews, 31, 6-16.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.smrv.2020.101311\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Short, M. A., Booth, S. A., Omar, O., Ostlundh, L., &amp; Arora, T. (2020). The relationship between sleep duration and mood in adolescents: A systematic review and meta-analysis. Sleep Medicine Reviews, 52, 101311.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.smrv.2007.07.007\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Meerlo, P., Sgoifo, A., &amp; Suchecki, D. (2008). Restricted and disrupted sleep: Effects on autonomic function, neuroendocrine stress systems and stress responsivity. Sleep Medicine Reviews, 12(3), 197-210.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1155\/2010\/759234\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Balbo, M., Leproult, R., &amp; Van Cauter, E. (2010). Impact of sleep and its disturbances on hypothalamo-pituitary-adrenal axis activity. International Journal of Endocrinology, 2010, 759234.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.smrv.2017.10.002\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Dalfsen, J. A., &amp; Markus, C. R. (2018). The influence of sleep on human hypothalamic-pituitary-adrenal axis reactivity: A systematic review. Sleep Medicine Reviews, 39, 187-194.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1007\/s00424-011-1044-0\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Besedovsky, L., Lange, T., &amp; Born, J. (2012). Sleep and immune function. Pfl\u00fcgers Archiv, 463, 121-137.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1038\/s41577-019-0190-z\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Irwin, M. R. (2019). Sleep and inflammation: Partners in sickness and in health. Nature Reviews Immunology, 19, 702-715.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.7326\/0003-4819-141-11-200412070-00008\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Spiegel, K., Tasali, E., Penev, P., &amp; Van Cauter, E. (2004). Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of Internal Medicine, 141(11), 846-850.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.7326\/0003-4819-157-8-201210160-00005\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Broussard, J. L., Ehrmann, D. A., Van Cauter, E., Tasali, E., &amp; Brady, M. J. (2012). Impaired insulin signaling in human adipocytes after experimental sleep restriction: A randomized, controlled study. Annals of Internal Medicine, 157(8), 549-557.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1038\/ijo.2013.114\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">St-Onge, M. P., Wolfe, S., Sy, M., Shechter, A., &amp; Hirsch, J. (2014). Sleep restriction increases the neuronal response to unhealthy food in normal-weight individuals. International Journal of Obesity, 38, 411-416.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.3945\/an.115.008623\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Dashti, H. S., Scheer, F. A. J. L., Jacques, P. F., Lamon-Fava, S., &amp; Ordov\u00e1s, J. M. (2015). Short sleep duration and dietary intake: Epidemiologic evidence, mechanisms, and health implications. Advances in Nutrition, 6(6), 648-659.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.cub.2019.01.069\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Depner, C. M., Melanson, E. L., Eckel, R. H., et al. (2019). Ad libitum weekend recovery sleep fails to prevent metabolic dysregulation during a repeating pattern of insufficient sleep and weekend recovery sleep. Current Biology, 29(6), 957-967.e4.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.3945\/an.116.012336\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">St-Onge, M. P., Mikic, A., &amp; Pietrolungo, C. E. (2016). Effects of diet on sleep quality. Advances in Nutrition, 7(5), 938-949.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.biopsych.2015.05.014\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Irwin, M. R., Olmstead, R., &amp; Carroll, J. E. (2016). Sleep disturbance, sleep duration, and inflammation: A systematic review and meta-analysis. Biological Psychiatry, 80(1), 40-52.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.neubiorev.2016.07.004\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Tobaldini, E., Costantino, G., Solbiati, M., Cogliati, C., Kara, T., &amp; Nobili, L. (2017). Sleep, sleep deprivation, autonomic nervous system and cardiovascular diseases. Neuroscience &amp; Biobehavioral Reviews, 74, 321-329.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.chest.2017.01.026\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Javaheri, S., &amp; Redline, S. (2017). Insomnia and risk of cardiovascular disease. Chest, 152(2), 435-444.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.jpain.2013.08.007\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Finan, P. H., Goodin, B. R., &amp; Smith, M. T. (2013). The association of sleep and pain: An update and a path forward. The Journal of Pain, 14(12), 1539-1552.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.sleep.2015.07.022\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Schrimpf, M., Teutsch, S., Weigl, L., &amp; Geisler, F. H. (2015). The effect of sleep deprivation on pain perception in healthy subjects: A meta-analysis. Sleep Medicine, 16(11), 1313-1320.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1126\/science.1241224\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Xie, L., Kang, H., Xu, Q., et al. (2013). Sleep drives metabolite clearance from the adult brain. Science, 342(6156), 373-377.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1038\/scientificamerican0316-44\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Nedergaard, M., &amp; Goldman, S. A. (2016). Brain drain. Scientific American, 314(3), 44-49.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1111\/ced.12455\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">OyetakinWhite, P., Suggs, A., Koo, B., et al. (2015). Does poor sleep quality affect skin ageing? Clinical and Experimental Dermatology, 40(1), 17-22.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1001\/jama.284.7.861\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Van Cauter, E., Leproult, R., &amp; Plat, L. (2000). Age-related changes in slow wave sleep and REM sleep and relationship with growth hormone and cortisol levels in healthy men. JAMA, 284(7), 861-868.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/s0022-3476(96)70008-2\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Van Cauter, E., &amp; Plat, L. (1996). Physiology of growth hormone secretion during sleep. Journal of Pediatrics, 128(5 Pt 2), S32-S37.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.2196\/16273\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Haghayegh, S., Khoshnevis, S., Smolensky, M. H., Diller, K. R., &amp; Castriotta, R. J. (2019). Accuracy of wristband Fitbit models in assessing sleep: Systematic review and meta-analysis. Journal of Medical Internet Research, 21(11), e16273.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1093\/sleep\/zsaa291\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Chinoy, E. D., Cuellar, J. A., Huwa, K. E., et al. (2021). Performance of seven consumer sleep-tracking devices compared with polysomnography. Sleep, 44(5), zsaa291.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.7326\/M14-2841\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Trauer, J. M., Qian, M. Y., Doyle, J. S., Rajaratnam, S. M. W., &amp; Cunnington, D. (2015). Cognitive behavioral therapy for chronic insomnia: A systematic review and meta-analysis. Annals of Internal Medicine, 163(3), 191-204.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1111\/jsr.12594\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Riemann, D., Baglioni, C., Bassetti, C., et al. (2017). European guideline for the diagnosis and treatment of insomnia. Journal of Sleep Research, 26(6), 675-700.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.5664\/jcsm.8986\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Edinger, J. D., Arnedt, J. T., Bertisch, S. M., et al. (2021). Behavioral and psychological treatments for chronic insomnia disorder in adults: An American Academy of Sleep Medicine clinical practice guideline. Journal of Clinical Sleep Medicine, 17(2), 255-262.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1111\/jsr.12371\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Borb\u00e9ly, A. A., Daan, S., Wirz-Justice, A., &amp; Deboer, T. (2016). The two-process model of sleep regulation: A reappraisal. Journal of Sleep Research, 25(2), 131-143.<\/a><\/li>\n\n\n\n<li>Czeisler, C. A., &amp; Klerman, E. B. (1999). Circadian and sleep-dependent regulation of hormone release in humans. Recent Progress in Hormone Research, 54, 97-130.<\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.cub.2013.06.039\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Wright, K. P., Jr., McHill, A. W., Birks, B. R., Griffin, B. R., Rusterholz, T., &amp; Chinoy, E. D. (2013). Entrainment of the human circadian clock to the natural light-dark cycle. Current Biology, 23(16), 1554-1558.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.cub.2016.12.041\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Stothard, E. R., McHill, A. W., Depner, C. M., Birks, B. R., Moehlman, T. M., Ritchie, H. K., Guzzetti, J. R., Chinoy, E. D., &amp; Wright, K. P. Jr. (2017). Circadian entrainment to the natural light-dark cycle across seasons and the weekend. Current Biology, 27(4), 508-513.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1212\/01.CON.0000427209.21177.aa\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Zee, P. C., Attarian, H., &amp; Videnovic, A. (2013). Circadian rhythm abnormalities. Continuum, 19(1 Sleep Disorders), 132-147.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1073\/pnas.1418490112\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Chang, A. M., Aeschbach, D., Duffy, J. F., &amp; Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232-1237.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1152\/japplphysiol.00165.2011\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Cajochen, C., Frey, S., Anders, D., et al. (2011). Evening exposure to a light-emitting diodes television screen affects circadian physiology and cognitive performance. Journal of Applied Physiology, 110(5), 1432-1438.<\/a><\/li>\n\n\n\n<li>Walker, M. P. (2017). Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner.<\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.jsmc.2016.10.012\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Grandner, M. A. (2017). Sleep, health, and society. Sleep Medicine Clinics, 12(1), 1-22.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.5665\/sleep.3298\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Buysse, D. J. (2014). Sleep health: Can we define it? Does it matter? Sleep, 37(1), 9-17.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1038\/s41598-017-03171-4\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Phillips, A. J. K., Clerx, W. M., O\u2019Brien, C. S., et al. (2017). Irregular sleep\/wake patterns are associated with poorer academic performance and delayed circadian and sleep\/wake timing. Scientific Reports, 7, 3216.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1016\/j.jacc.2019.12.054\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Huang, T., Mariani, S., &amp; Redline, S. (2020). Sleep irregularity and risk of cardiovascular events: The Multi-Ethnic Study of Atherosclerosis. Journal of the American College of Cardiology, 75(9), 991-999.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/doi.org\/10.1093\/sleep\/26.2.117\" target=\"_blank\" rel=\"noopener\" style=\"color:inherit;text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:rgba(41,83,142,.42)\">Van Dongen, H. P. A., Maislin, G., Mullington, J. M., &amp; Dinges, D. F. (2003). The cumulative cost of additional wakefulness: Dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep, 26(2), 117-126.<\/a><\/li>\n<\/ol>\n\n\n\n<p class=\"eq-lastrev\" style=\"margin:34px 0 0;font-family:&quot;Work Sans&quot;,sans-serif;font-size:11.5px;font-weight:700;letter-spacing:.15em;text-transform:uppercase;line-height:1.5;color:#5a6b7d\">Last reviewed September 2026<\/p>\n\n\n<\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"eq-rev\" style=\"margin-top:0px;margin-bottom:44px\"><a class=\"slp-next\" href=\"\/hypermobility-and-the-nervous-system\/\"><span class=\"eyb\">Read next<\/span><span class=\"ti\">Hypermobility and the Nervous System<\/span><span class=\"wy\">Another deep dive into a body system, and another article careful about the difference between what is established and what is still being worked out.<\/span><\/a><\/div>\n\n\n<\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-container-core-group-is-layout-d2a766d4 wp-block-group-is-layout-constrained\">\n\n\n<div class=\"eq-rev\" style=\"margin-top:0px;margin-bottom:0px\"><img loading=\"lazy\" decoding=\"async\" width=\"2560\" height=\"1708\" src=\"https:\/\/equilibriumpsychotherapy.net\/wp-content\/uploads\/2024\/06\/mid-shot-woman-therapist-taking-notes-clipboard-scaled.jpg\" alt=\"A therapist taking notes on a clipboard during a session, with the other person&#39;s hands clasped in front of them\" class=\"wp-image-230\" style=\"width:100%;height:340px;object-fit:cover;object-position:center 40%;border-radius:22px 22px 0 0;display:block\" srcset=\"https:\/\/equilibriumpsychotherapy.net\/wp-content\/uploads\/2024\/06\/mid-shot-woman-therapist-taking-notes-clipboard-scaled.jpg 2560w, https:\/\/equilibriumpsychotherapy.net\/wp-content\/uploads\/2024\/06\/mid-shot-woman-therapist-taking-notes-clipboard-300x200.jpg 300w, https:\/\/equilibriumpsychotherapy.net\/wp-content\/uploads\/2024\/06\/mid-shot-woman-therapist-taking-notes-clipboard-1024x683.jpg 1024w, https:\/\/equilibriumpsychotherapy.net\/wp-content\/uploads\/2024\/06\/mid-shot-woman-therapist-taking-notes-clipboard-768x512.jpg 768w, https:\/\/equilibriumpsychotherapy.net\/wp-content\/uploads\/2024\/06\/mid-shot-woman-therapist-taking-notes-clipboard-1536x1025.jpg 1536w\" sizes=\"auto, (max-width: 2560px) 100vw, 2560px\" \/><\/div>\n\n\n\n<div class=\"wp-block-group has-background eq-ondark has-global-padding is-layout-constrained wp-container-core-group-is-layout-f761ea3b wp-block-group-is-layout-constrained\" style=\"background-color:#29538e;border-radius:0px 0px 22px 22px;margin-top:0;margin-bottom:80px;padding:52px\">\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#c3d5ee;margin-top:0;margin-bottom:14px;font-size:12px;font-weight:700;letter-spacing:0.16em;line-height:1.4\">WORKING WITH THIS<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-text-color has-work-sans-regular-font-family\" id=\"when-sleep-is-the-thing-that-keeps-not-working\" style=\"color:#ffffff;margin-top:0;margin-bottom:18px;font-size:clamp(18.434px, 1.152rem + ((1vw - 3.2px) * 1.201), 29px);font-style:normal;font-weight:700;line-height:1.28\">When sleep is the thing that keeps not working<\/h3>\n\n\n\n<p class=\"has-text-color has-work-sans-regular-font-family wp-block-paragraph\" style=\"color:#d6e4f6;margin-top:0;margin-bottom:30px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.455), 18px);line-height:1.7\">Persistent sleep problems deserve more than being told to relax. If you have been lying awake for months, or sleeping enough and still waking unrefreshed, that is worth looking at directly rather than working around &#45; and if what is keeping you awake is stress, anxiety or something you have not been able to put down, that is worth talking about.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-text-color has-background has-work-sans-regular-font-family wp-element-button\" href=\"\/individual-session\/\" style=\"border-radius:9px;color:#2b302f;background-color:#fdf3da;padding:15px 30px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.284), 16.5px);font-weight:700\">Book a session<\/a><\/div>\n\n\n\n<div class=\"wp-block-button footer_b\"><a class=\"wp-block-button__link has-text-color has-work-sans-regular-font-family wp-element-button\" href=\"\/contact\/\" style=\"border-color:#93b3dd;border-width:1.5px;border-style:solid;border-radius:9px;color:#ffffff;padding:15px 30px;font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.284), 16.5px);font-weight:600\">Get in touch<\/a><\/div>\n<\/div>\n\n\n<\/div>\n\n\n<\/div>\n\n\n<\/div>\n\n\n<script>\n(function(){\n  var fig=document.querySelector('.slp-hyp');\n  if(!fig){ return; }\n  var gw=fig.querySelector('.gw'), hnd=fig.querySelector('.hnd');\n  var rect=fig.querySelector('#slphyprect'), edge=fig.querySelector('#slphypedge');\n  var cast=fig.querySelector('#slphypcast');\n  if(!gw){ return; }\n  if(!hnd){ return; }\n\n  var X0=46, X1=844, PPM=1.6625, LO=180, HI=480;\n  var REM=[[280.4,305.4],[450,494.9],[619.6,684.4],[729.3,809.1]], N3=[[165.7,250.5],[355.2,415.1],[559.7,589.6]];\n  var REMT=0, N3T=0, i;\n  for(i=0;i<REM.length;i++){ REMT=REMT+(REM[i][1]-REM[i][0]); }\n  for(i=0;i<N3.length;i++){ N3T=N3T+(N3[i][1]-N3[i][0]); }\n\n  var hh=fig.querySelector('.hh'), mm=fig.querySelector('.mm'), wk=fig.querySelector('.wk');\n  var d3=fig.querySelector('.d3'), dr=fig.querySelector('.dr'), live=fig.querySelector('.live');\n  var mins=HI, timer=null;\n\n  function kept(runs,x){\n    var t=0, j, a, b;\n    for(j=0;j<runs.length;j++){\n      a=runs[j][0]; b=runs[j][1];\n      if(x>a){ t=t+(Math.min(b,x)-a); }\n    }\n    return t;\n  }\n  function clock(m){\n    var t=(23*60+m)%1440, h=Math.floor(t\/60), n=t%60, ap='am';\n    if(h>=12){ ap='pm'; }\n    var h12=h%12;\n    if(h12===0){ h12=12; }\n    return h12+':'+(n<10?'0':'')+n+ap;\n  }\n  function words(m){\n    var h=Math.floor(m\/60), n=m%60, s=h+' hour';\n    if(h!==1){ s=s+'s'; }\n    if(n>0){ s=s+' '+n+' minutes'; }\n    return s+', awake at '+clock(m);\n  }\n  function draw(){\n    var x=X0+mins*PPM;\n    rect.setAttribute('width',String(x));\n    cast.setAttribute('x',String(x));\n    cast.setAttribute('width',String(Math.max(0,844-x)));\n    edge.setAttribute('x1',String(x));\n    edge.setAttribute('x2',String(x));\n    if(mins<HI){ edge.removeAttribute('hidden'); }\n    else{ edge.setAttribute('hidden',''); }\n    hnd.style.left=(x\/860*100)+'%';\n    hh.textContent=String(Math.floor(mins\/60));\n    mm.textContent=(mins%60<10?'0':'')+(mins%60);\n    wk.textContent=clock(mins);\n    d3.style.transform='scaleX('+(kept(N3,x)\/N3T)+')';\n    dr.style.transform='scaleX('+(kept(REM,x)\/REMT)+')';\n    hnd.setAttribute('aria-valuenow',String(mins));\n    hnd.setAttribute('aria-valuetext',words(mins));\n  }\n  function say(){\n    if(timer){ clearTimeout(timer); }\n    timer=setTimeout(function(){\n      var x=X0+mins*PPM;\n      live.textContent=words(mins)+'. 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