Sleep: The Underrated Performance Drug

You cannot out-train a poor night's sleep. After 40, deep sleep — the slow-wave stage responsible for growth hormone release, memory consolidation, and immune repair — declines steeply unless you actively protect it.

Three habits move the needle more than any sleep gadget. First, a consistent wake time, weekends included. Second, morning sunlight within 30 minutes of waking, ideally for 10 minutes. Third, a cool, dark, screen-free wind-down window of 60 to 90 minutes before bed.

Alcohol is the most misunderstood sleep saboteur. It helps you fall asleep and destroys the second half of the night. If you are training hard, perimenopausal, or already sleeping poorly, two drinks with dinner is not a neutral act.

Track sleep for two weeks before you change anything. You'll learn more from a cheap notebook than from any wearable telling you a generic score.