Sleep & Recovery

This category covers two overlapping outcomes: falling and staying asleep, and recovering from training and stress. Behavioural sleep interventions have broad evidence, while most sleep-supplement trials report comparatively small effects. The rankings show that difference in evidence depth and effect size.

Behavioural and environmental evidence

For chronic insomnia, both the American Academy of Sleep Medicine and American College of Physicians guidelines identify cognitive behavioural therapy for insomnia (CBT-I) as first-line treatment. Head-to-head trials report more durable effects than sleeping pills without medication-dependence risk. Consistent wake times, morning light, and a cool, dark room also have evidence relevant to sleep timing and continuity.

Supplements: modest but real

Melatonin has its strongest evidence for circadian problems — jet lag, shift work, and delayed sleep phase — where it shifts the body clock. As a general sedative its effect is small: meta-analyses put the reduction in time-to-fall-asleep at roughly 7 minutes. Trials of low, physiologic doses (0.5–1 mg) report similar effects to larger 5–10 mg doses, which produce greater exposure and can increase next-day grogginess. Magnesium evidence is weak-to-moderate and concentrated in older adults and people with low status; glycine, L-theanine, and apigenin remain small or preliminary evidence bases.

Prescription sleep: comparative safety

The dual orexin receptor antagonists (DORAs) — suvorexant, lemborexant, daridorexant — promote sleep by blocking wakefulness signalling and generally carry less next-day impairment and dependence than older Z-drugs. Z-drugs such as zolpidem have efficacy evidence alongside dependence and complex-sleep-behaviour risk, resulting in lower Safety scores. Both classes are prescription-only and studied in clinical treatment contexts.

Recovery

On the recovery side, long-running Finnish cohort studies associate frequent sauna use with lower cardiovascular and all-cause mortality, although confounding remains possible. Cold-water immersion may reduce acute soreness and affect mood, but recovery findings are mixed. Studies also report attenuated hypertrophy adaptation when cold immersion immediately follows resistance training.