Why You're Always Tired - 7 Myths Ruining Your Sleep

2022-12-09 · Long video (solo, talking head or whiteboard) · Ali, Russell Foster · recording, 11:04 · watch on YouTube

Topic: Health, sleep and habits · mode: List of tips or lessons · tags: Evidence-based framing, Lesson from a book

With clips from his Deep Dive interview with Oxford sleep scientist Russell Foster, Ali debunks seven sleep myths: timing matters as much as hours, eight hours is an average rather than a rule, waking at the same time need not be pedantic, blue light before bed barely matters, sleep apps deserve little trust, melatonin does little and polyphasic sleep hurts productivity.

What is said

The parts of the video and what is said in each (★ — how much it matters to the video).

00:00:00 — Always tired: sleep anxiety, Why We Sleep and the interview with Russell Foster

★★ Ali cites surveys showing that adults in the US feel tired on three days of the week on average, and that 30 to 48% of adults have trouble sleeping. — 00:00:00
★★★ Ali says that for many people the problem is not how much they sleep but anxiety about sleep, caused by believing sleep myths. — 00:00:00
★★ Ali calls Matthew Walker's Why We Sleep very good but says it set off a craze of fearing Alzheimer's and heart problems without eight hours; such sleep anxiety paradoxically makes sleeping harder. — 00:00:29
★★ Ali recently interviewed Professor Russell Foster, a sleep scientist with his own lab at the University of Oxford, on his podcast Deep Dive. — 00:00:29 · Deep Dive, University of Oxford
★★ Ali calls "it doesn't matter when you sleep as long as you sleep enough" a myth: when we sleep is also very important. — 00:00:58

00:01:20 — Myth 1: it doesn't matter when you sleep — circadian rhythm and chronotypes

★★★ Russell Foster says circadian rhythms underpin almost every aspect of our health and wellbeing, the point he wanted to get across in his book Life Time. — 00:01:27
★★ Ali says that in the 1990s Russell Foster's group discovered cells in the eye that only detect light; they tell the brain the time of day and help regulate the internal clock. — 00:01:27
★★ Ali says Foster's group found that people whose circadian rhythm is disrupted, by jet lag or night shifts, have more stress hormones, a higher risk of heart disease, get sick more often and are prone to emotional and cognitive problems. — 00:01:56
★★ Russell Foster says night-shift workers who do not adapt to working at night are working against their entire biology, which tells them to be asleep. — 00:02:26
★★ Ali explains that internal clocks are not all set the same way: being a morning person or a night owl is a person's chronotype, set by a natural inclination to sleep at a certain time. — 00:02:26
★★★ Ali advises organising your activities around your chronotype: a morning person may put creative and highest-focus work in the morning, while a night owl who controls their schedule can do focused work at night. — 00:02:55
★★ Ali tried hard to become a morning person, waking at six to go to the gym, but found it a nightmare; he now wakes around 7 to 7.30, sees himself as middle-of-the-day, writes his book in the morning and does calmer things in the evening. — 00:03:24 · Feel-Good Productivity (book)
★★★ Ali calls the idea that everyone needs eight hours of sleep a myth: there is a lot of variation in how much sleep people need. — 00:03:24

00:03:49 — Myth 2: everyone needs eight hours of sleep

★★★ Russell Foster objects that an average value is taken as the optimum for everyone: healthy sleep ranges from about six hours, or slightly less, to 10 or 11 hours, with great individual variation. — 00:03:53

“an average value is taken as the optimum value for all of us and of course it isn't”
★★★ Instead of counting hours, Ali suggests checking whether you woke naturally without an alarm (then you probably slept enough), whether waking took long, whether you needed caffeine, and whether you acted mean or annoying that day. — 00:04:25

00:04:54 — Myth 3: we should wake up at the same time every day

★★ Citing Russell Foster, Ali says it is generally good to wake up at the same time each day, but there is no need to be overly pedantic about it. — 00:04:54
★★ Russell Foster says regular timing of waking, eating and light exposure reinforces the signals that regulate the circadian system and stabilises it. — 00:04:54
★★ Ali says circadian rhythms change over life: teenagers often have an evening chronotype and struggle to wake, and by our late 50s or early 60s we keep the hours we kept at 10. — 00:05:24

00:05:48 — Myth 4: you should avoid blue light before sleep

★★ Ali paid his optician an extra £100 for a blue-light filter on his glasses because it was said to be better for sleep, but has learned that this is apparently a bit of a myth. (hedged) — 00:05:48
★★★ Russell Foster says a Harvard study, in which people read a Kindle at full brightness for four hours before bed on five nights, delayed sleep onset by only 10 minutes: statistically significant but biologically meaningless. — 00:06:19 · Kindle

“it may be statistically significant, but it's biologically meaningless”
★★★ Ali is glad to hear it: he now reads his Kindle with the backlight on without worrying about getting too much blue light. — 00:06:19 · Kindle

00:06:45 — Myth 5: sleep apps help you sleep better

★★ Ali got into sleep tracking with the Oura Ring, currently uses an Eight Sleep mattress, which he admits is quite good, and used to track all his sleep data. — 00:06:48
★★ Ali found that a low sleep readiness score, such as 54%, made him decide he felt worse than he did: the tracking apps gave him a negative placebo effect. — 00:06:48
★★ Russell Foster says that, at the moment, no sleep apps are endorsed by any sleep federation or approved by the FDA. — 00:06:48
★★ Russell Foster says the validation papers of many sleep apps show them working for eight undergraduates in California, and that one algorithm cannot judge good sleep, since sleep changes with age and between individuals. — 00:07:32
★★★ Ali's takeaway: a sleep score is nice for people who love optimising, but your body's signals, such as feeling rested on waking, needing an alarm and how you feel all day, matter far more than an app's score. — 00:07:32

00:08:15 — Myth 6: melatonin helps us sleep better

★★ Russell Foster says the best study ever undertaken found melatonin before bed cuts the time to fall asleep by 30 minutes, while many studies found no effect at all. — 00:08:29
★★ Ali says that best study, from 2007, gave autistic children small daily doses of melatonin for three months, and they fell asleep 30 minutes sooner; a 2013 meta-analysis found melatonin cuts the time to fall asleep by about seven minutes on average. — 00:08:29
★★ Ali calls Russell Foster's 2022 book Life Time really good and up to date on melatonin; he listened to it on Audible. — 00:08:58 · Audible
★★ Following Russell Foster, Ali concludes that melatonin does not make much difference: it might help with jet lag, but not in day-to-day life. — 00:08:58

00:09:41 — Myth 7: polyphasic sleep is good for your productivity

★★ Russell Foster says all the data suggest that polyphasic schedules, with a total of four to six hours of sleep split between the night and fragments in the day, are a really bad idea. — 00:09:57
★★★ Polyphasic sleep gives more waking hours in theory, but, as Foster says, the work done in them is of lower quality, because people are more exhausted, less productive and less creative. — 00:09:57
★★ Ali cites studies showing students on polyphasic sleep do worse in exams than those on normal sleep, and concludes that splitting sleep does not help productivity, whatever blogs like Lifehacker suggest. — 00:10:26

Threads in this video

shift · How do you sleep better? — Ali calls the idea that everyone needs eight hours of sleep a myth: there is a lot of variation in how much sleep people need. (00:03:24)
refine · How do you sleep better? — Instead of counting hours, Ali suggests checking whether you woke naturally without an alarm (then you probably slept enough), whether waking took long, whether you needed caffeine, and whether you acted mean or annoying that day. (00:04:25)
restate · How do you sleep better? — Russell Foster objects that an average value is taken as the optimum for everyone: healthy sleep ranges from about six hours, or slightly less, to 10 or 11 hours, with great individual variation. (00:03:53)
first on record · Should you avoid blue light before bed? — Ali, who had paid an extra £100 for a blue-light filter on his glasses, now calls avoiding blue light before sleep a bit of a myth and reads his Kindle with the backlight on without worrying. (00:06:19)
first on record · Should you track your sleep with an app or a device? — Ali's takeaway: a sleep score is nice for people who love optimising, but your body's signals, such as feeling rested on waking, needing an alarm and how you feel all day, matter far more than an app's score. (00:07:32)
refine · How should you plan your day? — Ali advises organising your activities around your chronotype: a morning person may put creative and highest-focus work in the morning, while a night owl who controls their schedule can do focused work at night. (00:02:55)
milestone · Ali's interview podcast with entrepreneurs and creators (2021) — Ali recently interviewed Professor Russell Foster, a sleep scientist with his own lab at the University of Oxford, on his podcast Deep Dive. (00:00:29)

Where the stories that moved here went next

Ali's interview podcast with entrepreneurs and creators (2021) — running; last: milestone, 2023-10-27

Mentioned

Central: circadian rhythm · Russell Foster · sleep anxiety

Also: People: Matthew Walker

Projects: Deep Dive

Works: Feel-Good Productivity (book) · Life Time · Why We Sleep

Organizations: Eight Sleep · Harvard University · Lifehacker · University of Oxford

Concepts: Alzheimer's disease · blue light · cardiovascular disease · chronotype · melatonin · polyphasic sleep · sleep fitness

Places: California

Products: Audible · Kindle · Oura Ring

Also centred on circadian rhythm: My Evidence-Based Sleep Routine

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