I am taking part in an MDS medical study right now. One of the restrictions is that you can't take caffeine within 48 hours of the study. It is for four weekends. I usually take a caffeine pill before every workout. I had to skip it yesterday (since I am here at the study right now). I just have a harder timed getting pumped about the workout. Anybody else here use caffeine or another stimulant before their workouts?