The increasing power of the male tennis game, as evidenced in new Wimbledon champion Goran Ivanisevic's thundering serves, is unlikely to be explained by creatine loading, if the results of a new study from Belgium - the home of women's runner-up Justine Henin - are to be believed.

The study, involving eight well-trained young male tennis players, was designed to investigate the effect of acute creatine supplementation on stroke quality during simulated match play.

Over the last decade creatine has become one of the most popular nutritional supplements in sports, including tennis. Short-term supplementation has been shown to improve power output during various modes of short all-out sprint exercise, repeated jumping and various types of resistance exercises. Furthermore, some findings suggest that the performance benefits are greatest during short maximal intermittent exercise bouts, of the type which feature in tennis.

Thus, hypothesised the researchers, creatine supplementation might improve stroke performance in tennis by acting directly on arm force and power and/or by enhancing intermittent sprint performance, allowing for better positioning at the time of stroke execution.

In the double-blind study, the subjects were assigned in random order to two six-day experimental protocols, separated by a five-week 'wash-out period'. For the first five days of each protocol the subjects were supplemented either with creatine (20g of creatine monohydrate powder per day) or a similar-tasting placebo (inactive substance). On day six they performed the Leuven Tennis Performance test, which aims to evaluate stroke quality in competition tennis players in match-like conditions, featuring four games of 10 rallies each.

When the results of the two sets of tests were analysed and compared, the researchers found that creatine loading did not significantly impact on either the power or precision of the subjects' strokes. 'Thus,' they conclude, 'the current data clearly demonstrate that there is no performance benefit of acute high-dose creatine supplementation in elite tennis players.'

However, they do not rule out the possibility that long-term creatine intake, with its stimulatory effect on muscle growth, might still be a factor in enhancing stroke quality and sprint power in the game.

Int J Sports Med 2001 Jan 22(1) p76-80

Isabel Walker