Sleep

400 mg of caffeine six hours before bed cost over an hour of sleep nobody noticed. Late exercise did no harm across 23 studies; a later…

A 40–42.5 °C bath one to two hours before bed cut sleep onset by about 10 minutes. The tea and the candle have no recorded effect…

A single all-nighter dropped protein synthesis 18% in a crossover trial — cortisol up 21%, testosterone down 22%. The reverse has never been measured.

Sleep difficulty runs 40–56% through peri- and postmenopause against 31% before it. In recorded sleep, flash-related waking was 27% of total time awake.

You run four to six cycles a night and can surface between them. Waking most nights for weeks, gasping, or three bathroom trips is a different…

The adult recommendation has no upper bound at all — the CDC closes it only at 61 and over. Nobody official names eight as the number…

Pooled trials put a 107 mg coffee at 8.8 hours before bed and a 217 mg pre-workout at 13.2. Half-life alone ranges from 2.3 to 9.9…

Room light under 200 lux delayed melatonin onset in 99% of people. Lab sleep showed no difference between 13 °C and 23 °C with normal bedding.

Getting out of bed when you're frustrated is stimulus control, a graded AASM recommendation. Paradoxical intention, sold as proven, has insufficient data.

Stimulus control — out of bed after 20 minutes, bed for sleep only — is the part AASM backs. The snooze button, ranked first, fails its…

Only a warm bath at 40–42.5 °C and a caffeine cut-off hold up in trials. For many of the 30.5% sleeping under seven hours, no checklist…