Sleep foundations

Sleep is the highest-leverage foundation — fix consistency and light before chasing gadgets or supplements.

Start today

Pick one wake time you can keep every day this week, including weekends, and get bright light in your eyes within an hour of waking.

Why it matters

A regular schedule and light exposure set the body clock that governs energy, appetite, mood and recovery. Most sleep problems improve from timing and environment before anything else.

The evidence (strong)

Consistent sleep timing, morning light, cool/dark rooms and caffeine timing are the best-evidenced levers. Both short and highly irregular sleep are linked to worse metabolic, cardiovascular and cognitive outcomes.

Where it's thin: Individual sleep need varies (most adults 7–9 h). Chasing a specific "deep sleep %" from a wearable is lower-yield than fixing schedule and light, and consumer sleep-stage accuracy is limited.

How to do it

• Same wake time every day
• Morning daylight within an hour of waking
• No caffeine after early afternoon
• Cool, dark, quiet room; screens down 30–60 min before bed
• A simple wind-down routine signals the brain it is time
• Keep the bed for sleep so your brain links the two
• Anchor the schedule even on weekends (limit drift to ~1 h)
• Watch alcohol and late heavy meals — both fragment sleep
• If you nap, keep it short and early so it does not steal night sleep
• Consistency (low night-to-night variability) predicts outcomes independently of duration
• Light timing shifts your clock: morning light advances, late-night light delays — use deliberately for jet lag or shift work
• If sleep stays broken despite good habits, screen for sleep apnoea rather than adding supplements

Safety — read before starting

Loud snoring, gasping or unrefreshing sleep despite good habits may signal sleep apnoea — worth evaluating, as it affects heart and brain health.