Because many products are nonfat, they have added sugar. In effect, people tend to overindulge in carbohydrates and overeat. I recently attended a lecture where they said that caffeine could enhance athletic and aerobic performance. I know the US Olympic Committee bans it. Caffeine also acts as a diuretic, therefore places the athlete at risk for dehydration during an event.
Creatine phosphate is a high-energy compound stored in muscle.
It is claimed to increase creatine phosphate contents in muscle, increase energy and stimulate muscle growth. Preliminary research suggests consuming 20 to 25 grams of Creatine to increase power in short term, high intense exercise. It also appears to increase body weight, due to gain of either muscle protein or water. Unfortunately additional research is needed to confirm these benefits. If Creatine is proved effective as a dietary supplement, it dosing good be considered doping, because the amount that you would have to take in could not be supplied by the diet alone.