Sleep duration & health: what the research actually says

Q: How do I track sleep duration & health?

SleepShred logs it in about 20 seconds a day and then compares your nights with and without it, so you see the effect on your own sleep instead of the study average.

Q: Is SleepShred free?

No. SleepShred Pro is $4.99 per month or $29.99 per year, with no free trial and no ads. Everything stays on your iPhone.

How much sleep adults actually need, what happens below seven hours, and why you stop noticing the impairment long before it stops happening.

All studies · 6

Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research SocietyWatson NF, Badr MS, Belenky G, et al. · Sleep 38(6):843–844 · 2015Adults should sleep ≥7 h per night on a regular basis; <7 h is associated with weight gain, diabetes, hypertension, depression and mortality.National Sleep Foundation's sleep time duration recommendations: methodology and results summaryHirshkowitz M, Whiton K, Albert SM, et al. · Sleep Health 1(1):40–43 · 20157–9 h recommended for adults 26–64; 7–8 h for 65+.Trends in self-reported sleep duration among US adults from 1985 to 2012Ford ES, Cunningham TJ, Croft JB · Sleep 38(5):829–832 · 2015Population sleep has shortened; the share of adults sleeping ≤6 h rose to ~29%.The effects of sleep extension on the athletic performance of collegiate basketball playersMah CD, Mah KE, Kezirian EJ, Dement WC · Sleep 34(7):943–950 · 2011Extending sleep to ~10 h improved sprint time, shooting accuracy, reaction time and mood.Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studiesCappuccio FP, D'Elia L, Strazzullo P, Miller MA · Sleep 33(5):585–592 · 2010Both short (<7 h) and long (>8–9 h) habitual sleep are associated with higher mortality — a U-shaped curve.The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivationVan Dongen HP, Maislin G, Mullington JM, Dinges DF · Sleep 26(2):117–126 · 2003Two weeks at 6 h/night produced deficits equal to two nights of total deprivation — while subjects felt only mildly sleepy. You adapt to feeling tired, not to being impaired.

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Frequently asked questions

What does the research say about sleep duration & health?

Adults should sleep ≥7 h per night on a regular basis; <7 h is associated with weight gain, diabetes, hypertension, depression and mortality.

How do I track sleep duration & health?

SleepShred logs it in about 20 seconds a day and then compares your nights with and without it, so you see the effect on your own sleep instead of the study average.

Is SleepShred free?

No. SleepShred Pro is $4.99 per month or $29.99 per year, with no free trial and no ads. Everything stays on your iPhone.

Track it, don't guess it

SleepShred turns this research into a 20-second daily habit: log your night, see which of your own behaviours move your sleep, and screen for the disorders nobody diagnoses.

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Educational summary of published research, not medical advice. Screening scores are not diagnoses. If a score is elevated or you feel unwell, talk to a clinician.