Sleep hygiene
What actually works, ranked by evidence
Most sleep hygiene advice is recycled folklore with weak studies behind it. Some interventions, though, have very strong evidence — stronger than any sleep supplement. Here's the honest ranking, with mechanism and implementation for each.
Interventions
- 01
Sleep hygiene — what actually works vs what doesn't
Strong evidenceThe full ranked list. Most of what's marketed as sleep hygiene has weak evidence — a few interventions have very strong evidence.
- 02
Room temperature for sleep — the optimal range
Moderate evidence16–19°C / 60–67°F. The mechanism is core body temperature drop, and why your bedding choices interact with this.
- 03
Light exposure — morning light and evening light
Strong evidenceMorning bright light is the most powerful circadian lever you have. Stronger than any supplement, and free.
- 04
Exercise and sleep — timing and type
Moderate evidenceRegular exercise improves sleep quality. The 'don't exercise late' rule is overstated for most people.
- 05
Screens before bed — honest evidence review
Limited evidenceThe blue-light story is partially correct. The arousal-from-content story is probably bigger. What the studies actually compared.
- 06
What to eat and drink for better sleep
Limited evidenceMost 'sleep foods' have weak evidence. The few that move the needle: protein timing, late carbs, alcohol restriction.
- 07
CBT-I explained — the gold standard for insomnia
Strong evidenceThe first-line treatment for chronic insomnia, per every major guideline. Equally effective as medication short-term, more effective long-term.
- 08
Sleep restriction therapy — how it works
Strong evidenceThe most counterintuitive insomnia intervention: temporarily cut sleep to rebuild sleep drive. Why it works.
- 09
Napping — when it helps and when it doesn't
Moderate evidence10–20 min before 3pm: beneficial. 30+ min or later in the day: usually worse than no nap. The reason involves sleep inertia.