Timing your coffee intake for peak cognitive alertness has less to do with cortisol spikes and more to do with leveraging the biology of adenosine. Caffeine works by blocking adenosine, a molecule that builds up the longer you’re awake and makes you feel tired. But right after waking, adenosine levels are at their lowest, meaning there’s not much for caffeine to block. That initial “jolt” you feel from your first sips? It’s often just natural sleep inertia fading (or maybe the placebo effect fro