SleepShred
A review of caffeine's effects on cognitive, physical and occupational performance
McLellan TM, Caldwell JA, Lieberman HR · Neuroscience & Biobehavioral Reviews 71:294–312 · 2016
Key finding
Caffeine restores performance lost to sleep deprivation but does not exceed the rested baseline — no free passes.
Citation
Related guides
Related studies
Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed400 mg caffeine taken even 6 h before bed cut objective sleep by >1 h — while subjects barely noticed.The effect of caffeine on subsequent sleepCaffeine reduced total sleep by ~45 min and efficiency by 7%. To avoid effects, a coffee (~107 mg) should be ~8.8 h before bed; a pre-workout dose (~217 mg) ~13 h.Coffee, caffeine, and sleepCaffeine prolongs sleep latency, reduces total sleep and deep sleep; sensitivity varies with genetics and habitual use.Sustaining executive functions during sleep deprivationStimulants patch alertness but not higher-order judgement after sleep loss.Wake up and smell the coffeeCaffeine is ergogenic for endurance, strength and power — which is why timing (not abstinence) is the lever.
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.
Get SleepShred for iPhoneEducational 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.