Why is coffee so good at giving a boost?

Jason Rihel - So, that is because of what's in coffee which is caffeine and caffeine is an adenosine receptor antagonist.

So, in order to understand how this works, one concept for the timer for what maintains wakefulness is thought to be in fact adenosine which is a small molecule that gets progressively secreted in the brain and builds up during wakefulness. In certain areas of the brain, it's thought that adenosine is triggering, "Hey, it's time to go to sleep now." Caffeine is thought to directly interfere with that signal that it's time to go to sleep and give in fact a boost to wakefulness.