Sleep & Longevity

Bright light in the first hour after waking sets your circadian rhythm and anchors your body clock so melatonin rises at the right time. Get it outdoors if you can, since indoor or window light is often too dim to count.

Caffeine has a 5-6 hour half-life, so a 2 PM coffee is still half-strength at 8 PM. In a controlled study, 400 mg taken six hours before bed cut total sleep by more than an hour. Make lunch the last coffee; herbal tea or decaf after.

Source: Drake 2013 — J Clin Sleep Med

Your body needs to cool down a few degrees to fall asleep. A cool room helps that happen, and it is one of the simplest changes to make.

Even small amounts of light suppress melatonin. Use blackout curtains or a quality sleep mask, and cover or remove LED indicators.

Your body clock depends on regularity. In 61,000 UK adults wearing activity trackers, how regular their sleep was predicted mortality better than how long they slept. Sleeping in on weekends creates "social jet lag" that throws off the week.

Source: Windred 2024 — SLEEP

Dim lights, put screens away, and do a calming routine (tea, stretching, reading). Your brain learns to recognize that bedtime is coming.

Digesting a large meal is work your body would rather not do while it is trying to wind down. Aim for a 2-3 hour buffer between your last meal and bedtime.

Alcohol helps you fall asleep faster, but at every dose it fragments the second half of the night, and at higher doses it cuts REM. Even one or two drinks close to bed measurably disrupt sleep.

Source: Ebrahim 2013 — Alcohol Clin Exp Res

If you work, watch TV, or eat in bed, your brain stops associating it with sleep. Reserve it exclusively, and you'll fall asleep faster when you lie down.

Don't check the time (this increases anxiety). Get up, do a calm dim activity until sleepy, then return. Lying awake trains your brain to associate bed with frustration.

A short, well-timed nap boosts alertness without disrupting nighttime sleep. Longer or later naps borrow from sleep quality.

If you've optimized your environment and routine but still sleep poorly, undiagnosed conditions (sleep apnea, thyroid, deficiencies) can be easily missed. Loud habitual snoring, witnessed breathing pauses, or waking unrefreshed are worth mentioning, since they can signal treatable sleep apnea. Professional testing is worth it before any supplement or medication.

Use a wearable or sleep app to monitor deep sleep and REM. Even with 7-8 hours in bed, broken sleep cycles reduce the benefit. Tracking can surface patterns you would otherwise miss.

A 10-minute warm soak an hour or two before bed warms your skin so your core temperature drops faster afterward, the body's trigger for sleep onset. Warming up first helps you cool down into sleep. No bath handy? Warm socks or a brief footbath work the same way.

Source: Haghayegh et al. 2019 — Sleep Medicine Reviews

Bright, blue-rich light before bed suppresses melatonin and pushes your body clock later; warm, low lamps preserve the natural melatonin rise. Keep evening rooms dim and amber, not bright and white. For a nighttime bathroom trip, a dim red or amber nightlight disturbs your clock far less.

Source: Gooley et al. 2011 — J Clinical Endocrinology & Metabolism

Food is a powerful timing cue for the clocks in your liver and metabolic tissues, so keeping meals at consistent times helps keep your whole-body clock aligned with your sleep clock. In one trial, shifting meals 5 hours later shifted blood-glucose rhythms by nearly 6 hours.

Source: Wehrens et al. 2017 — Current Biology

A couple of hours before bed, write each nagging worry in one column and its next concrete step in a second column, then close the notebook. Offloading and problem-solving early lowers pre-sleep mental arousal so racing thoughts don't ambush you at lights-out.

Source: Carney & Waters 2006 — Behavioral Sleep Medicine