Caffeine Timing

The article says delaying caffeine for 90 minutes prevents the afternoon crash by allowing adenosine to clear naturally and the cortisol awakening response to complete. Coffee timing should consider the natural cortisol rhythm after waking. A general recommendation is to delay coffee for about 90 minutes after waking. Wolves who wake later may time coffee around 11 AM, though forced early waking can change what is useful. Caffeine blocks adenosine receptors, masking tiredness without removing adenosine. Residual adenosine remains in circulation for the first 60–90 minutes after waking. The article attributes the early-afternoon energy crash to accumulated adenosine becoming active after caffeine clears. Adding caffeine while cortisol is high can make some people jittery.