Well I don't drink coffee (i can't remember if I've ever finished a cup), and I love to sleep (not an early bird). I can tell you that I have to wake up at Retty early hours (like 5 in the morning or earlier, never the same hour) due to my work, and I never feel sleepy the way coffee drinkers do. Neither I need to exercise. I am also aboe to have heavy breakfasts very early, unlike coffee drinkers who usually can't eat more than a toast. I don't know that many people who doesn't drink coffee, so I don't know if my experience is common or not.