Creatine supplementation is considered to enhance performance of repeated bouts of high-intensity exercise. We have therefore determined the effect of creatine supplementation for a simulated basketball tournament. The study was a double-blind randomized crossover, in which 6 male and 6 female elite basketball players completed a tournament consisting of one simulated game per day for three consecutive days. For five days prior to the first game, half the subjects ingested 0.1 g of creatine per kg of body mass, dissolved in 250 ml of an 8% carbohydrate sport drink, 4 times per day. They ingested a maintenance dose of 0.04 g/kg during the tournament. The other subjects consumed a placebo (glucose) in the same manner. After a washout period of 28 d, subjects crossed over for the creatine and placebo treatments and repeated the tournament. Results from a time-motion study of Australian elite male basketballers were used to design the simulated game, which consisted of a 10-min warm up followed by eight ~5-min circuits with rests of 0.5-5 min between circuits. Each circuit consisted of three maximal 20-m shuttles, five submaximal 40-m shuttles, one maximal and three submaximal defensive shuffles, one set of 10 maximal jumps, and one goal-shooting activity in a fixed order. Performance was recorded for maximal activities and goal shooting. Blood samples were collected at regular intervals for measurement of lactate concentration. Repeated-measures mixed modeling was used to analyze effects as percent change (with 95% likely range). Creatine increased body mass by 0.9% (0.5 to 1.2%), presumably by increasing fluid retention in muscle cells. Creatine decreased blood lactate by 0.4 mmol.L-1 (-0.2 to 1.0 mmol.L-1), which is consistent with less use of the anaerobic glycolytic pathway to meet energy demands. There was little effect on performance averaged over the tournament, but during the tournament (Day 3 minus Day 1) creatine produced the following effects relative to placebo: from start to finish of a game, jump height increased 8.5% (-3.0 to 20%), shuffle speed increased 5.1% (0.4 to 9.9%), but sprint speed decreased 2.7% (-0.2 to 5.7%); successful goal shooting with creatine also increased 9.7% (2.9 to 17%) by Day 3, although with creatine shooting percentage was substantially lower on Day 1. This change in goal-shooting success was unexpected and warrants further study. Creatine appears to improve some measures of performance of elite basketball players during a game on the last day of a simulated tournament relative to the first day. However, creatine has negligible effect on average performance over a tournament, so it is probably not a beneficial supplement for basketball and similar high-intensity sports.
© Copyright 1999 5th IOC World Congress on Sport Sciences with the Annual Conference of Science and Medicine in Sport 1999. Alle Rechte vorbehalten.