Health, Fitness & Human Performance
The highest-leverage health intervention most people ignore.
9 topics · 9 curated works
No prior grounding assumed.
Benefits of Napping in Healthy Adults: Impact of Nap Length, Time of Day, Age, and Experience with Napping
Catherine E. Milner & Kimberly A. Cote · 2009
Reviews the nap research and concludes short naps improve alertness and performance reliably, while longer naps add memory benefits at the cost of…
+2 more at this level
Assumes you know the vocabulary.
Shift Work and Disturbed Sleep/Wakefulness
Torbjörn Åkerstedt · 2003
Argues shift work sleep problems come from fighting the circadian clock rather than from the work itself, and that rotating and night schedules cause…
+4 more at this level
Primary sources and full treatments.
Patterns of Performance Degradation and Restoration During Sleep Restriction and Subsequent Recovery: A Sleep Dose-Response Study
Gregory Belenky et al. · 2003
Restricts subjects to three, five, seven or nine hours of sleep for a week and shows three nights of recovery sleep restores alertness but not the…
9 works
Catherine E. Milner & Kimberly A. Cote
Reviews the nap research and concludes short naps improve alertness and performance reliably, while longer naps add memory benefits at the cost of grogginess on waking.
Christopher Drake, Timothy Roehrs, John Shambroom & Thomas Roth
Shows a standard dose of caffeine taken six hours before bedtime still measurably disrupts sleep, even when the person does not report feeling less sleepy.
link checked 17 Sept 2026The Royal Institution
Argues that sleep is when the brain consolidates and prunes what was learned while awake, so sleep loss degrades memory formation itself rather than merely leaving you tired.
link checked 17 Sept 2026Torbjörn Åkerstedt
Argues shift work sleep problems come from fighting the circadian clock rather than from the work itself, and that rotating and night schedules cause measurably worse sleep and alertness than fixed ones.
Kenneth P. Wright Jr. et al.
Shows a week of camping without artificial light shifts people's circadian clocks nearly two hours earlier to match sunrise and sunset, evidence that modern lighting rather than biology is what desynchronises most people's clocks from day and night.
link checked 17 Sept 2026Leah A. Irish et al.
Reviews the individual components of standard sleep hygiene advice and finds most of them have never been tested well enough on their own to justify how confidently they are given.
link checked 17 Sept 2026Amir Qaseem et al.
Recommends cognitive behavioural therapy for insomnia as the first-line treatment ahead of sleep medication, based on trial evidence that CBT-I works as well with none of the drug risks.
link checked 17 Sept 2026Massimiliano de Zambotti et al.
Tests consumer sleep trackers against polysomnography and finds they estimate total sleep time reasonably well but are unreliable at identifying sleep stages, undermining the stage breakdowns the apps report with such confidence.
link checked 17 Sept 2026Gregory Belenky et al.
Restricts subjects to three, five, seven or nine hours of sleep for a week and shows three nights of recovery sleep restores alertness but not the reaction-time speed lost at the more severe restriction levels.
link checked 17 Sept 2026This subject genuinely sits in more than one domain. These fields approach the same ground with different methods.