Creatine and Endurance Training

Creatine is one of the hottest new supplements available. Even conservative sports medicine experts are lauding the value of supplementing creatine because of both its effectiveness and its lack of side effects. It's also just good science, since creatine phosphate serves as the backup for the most elemental energy source, adenosine triphosphate, or ATP.

Since the ATP-CP system provides only a few seconds of energy, most studies show that supplementing the diet with creatine provides benefits for high-intensity, shorter-duration exercise, such as bodybuilding workouts. The question is, Does creatine offer benefits for those who engage in endurance exercise? When Swedish researchers recently tested the effects of creatine on runners, nine of whom took supplemental creatine while the other nine took a placebo, they found not only that there was little effect from creatine loading, but also that the substance caused a slight detrimental effect in running performance. Even so, this so-called bad effect may actually be a boon to bodybuilders.

The scientists speculated that the decreased running times shown by a few of the runners in the study resulted from added muscle mass, which may have slowed them down. These runners showed a higher percentage of lactic acid, which resulted from a greater involvement of type-II muscle fibers, the fibers that primarily burn sugar under high-intensity conditions. Previous studies showed that long-term creatine supplementation appears to increase the diameter of type-II fibers, meaning it causes an increase in muscle size.

Although the researchers in this study didn't discuss the proposed muscle-building mechanism of creatine, the most likely explanation is that it promotes greater ATP replenishment in muscle. This would provide fuel for muscle protein synthesis reactions in muscle cells. The best way to supplement your diet with creatine is to take a five-gram dose six times a day for four days, then take two five-gram doses a day after that. Taking the creatine with hot water minimizes conversion of the creatine into creatinine, a waste product eliminated by the kidneys.