Caffeine timing for better deep sleep

You can fall asleep after an evening coffee and still lose sleep quality to it. Caffeine does not only delay sleep — it flattens the deep, slow-wave stages that do most of the restorative work.

The half-life problem

Caffeine's half-life is around five to six hours for most adults, and longer if you are pregnant, taking certain medications, or simply metabolise it slowly. A 3pm double espresso can leave a meaningful dose in your system at 11pm.

A practical cutoff

• —Aim to finish caffeine eight to ten hours before your target bedtime
• —For an 11pm bedtime, that means nothing after about 1pm to 3pm
• —Count tea, cola, energy drinks, dark chocolate, and pre-workout powders

If mornings are rough without it

Heavy morning reliance on caffeine can signal that sleep is not restorative. Persistent daytime sleepiness despite adequate time in bed deserves attention from a qualified healthcare professional because several different sleep and schedule factors can contribute.