Caffeine does not produce energy, as often advertised. It merely delays sleepiness by blocking adenosine. Caffeine binds to the very same receptors in the brain that are needed to bind adenosine. When caffeine attaches to the receptors, adenosine gets blocked from binding to the site. Remember, adenosine accumulates every hour we are awake. Therefore, when caffeine is on board, we don’t get as sleepy as we should because the adenosine is left in the system with nowhere to express its sleep signals.
