In previous issues of PEAK PERFORMANCE, we've reported that supplementing your diet with an amino acid called creatine might give you greater muscle strength during resistance training, faster running times during 1 000-metre intervals, and improved recovery following intense exercise. However, new research carried out with cyclists indicates that creatine ingestion has little positive impact on intense cycling efforts.

In a study carried out at McMaster University in Ontario, Canada, nine cyclists were tested after taking creatine, a placebo, or nothing at all. The creatine dosage was 20 grams per day for three days, and the three tests occurred 14 days apart. Biopsies taken from the athletes quadriceps muscles following creatine ingestion revealed that muscle creatine phosphate concentrations were not higher in the creatine group, compared to placebo and control groups. Not surprisingly, creatine supplementers did not have higher peak muscle strength or greater average muscle power during 10- or 30-second blasts of maximal exercise, nor were lactate or fatigue levels different between the groups.

Perhaps a longer period of creatine supplementation was needed to raise muscle creatine phosphate concentrations to performance-enhancing levels in the Ontario study. However, it's also possible that creatine simply doesn't aid sprint performances in cyclists. Overall, the creatine story, which once pointed to a very positive role for creatine during exercise, is now very confusing, since recent research showed that creatine actually slowed 6-K times for runners and boosted lactate levels while running at one-mile race speeds.

'The Effect of Oral Cr Supplementation on Muscle (PCr) and Power Output during a Short-Term Maximal Cycling Task,' Medicine and Science in Sports and Exercise, vol. 26(5), Supplement, p. S23, 1994