The effect of creatine supplementation on two 700-m maximal running bouts.

We investigated the effect of creatine supplementation on maximal running performance in a simulated track competition. Twelve competitive male runners were assigned to either a placebo or creatine supplementation group. Both groups completed two maximal 700-m running bouts 60 min apart on an outdoor track. A second identical trial was performed 7 days later, and for 5 days prior to the second trial, subjects ingested 20 g.day-1 of either creatine monohydrate or a placebo. Subjects in the placebo group ran 110.2 +/- 3.5 s and 110.4 +/- 3.0 s for the first trial and 108.5 +/- 2.9 s and 108.0 +/- 1.7 s for the second trial, while the creatine group ran 109.9 +/- 3.2 s and 110.4 +/- 3.6 s for the first trial and 109.7 +/- 3.3 s and 107.8 +/- 2.2 s for the second trial. There were no significant differences between groups by trial or Trial X Time for running time, postexercise blood lactate concentration, or body weight (p > .05). We concluded that creatine supplementation does not enhance performance of single or twice-repeated maximal running bouts lasting 90-120 s.