Caffeine curfew

Stop caffeine at lunch for 10 days and see whether your sleep notices. Pajdo keeps an eye on how long and how soundly you sleep.

That afternoon coffee may still be working when you'd rather be asleep. A 2023 review of 24 studies found caffeine cut total sleep by about 45 minutes and added time awake in the night. To avoid losing sleep, the authors suggest a regular coffee at least 9 hours before bed, and a pre-workout drink at least 13 hours before. In a smaller study, a strong dose 6 hours before bed still disturbed sleep. The American Academy of Sleep Medicine and the CDC both suggest skipping caffeine in the afternoon and evening.

For 10 days, have your last coffee, tea, cola or energy drink by lunch. Pajdo compares how long you sleep, how much of your time in bed is sleep, and wake-ups with your usual nights, all from your Apple Watch. The watch counts some time awake as sleep, so treat wake-ups as a rough guide.

One person's 10 days is a hint, not proof. Plenty else changes from night to night, so if you spot a difference, it's worth running it again.

This is general wellness information, not medical advice. If a number worries you, or stays away from your usual for a while, talk to a doctor.

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