Effect of 10% weight loss on simulated taekwondo match performance: a randomized trial.

The objective of the present study was to analyze the effect of 10% body mass reduction on simulated taekwondo match performance. Thirty-one male taekwondo athletes were randomly distributed in two groups: weight loss group (n= 15) - athletes in this group reduced 5% body mass per week during two successive weeks, totaling 10% body mass reduction; control group (n= 16) - athletes in this group kept their body mass constant during the 2-week period. Twenty-four hours before and after this period, athletes performed a simulated 3-round taekwondo match (6 min). Athletes wore body protectors to validate the scores during the match according to the official taekwondo rules. Match was filmed and actions were categorized using the Game Performance Assessment Instrument. There was a group and time interaction (< 0.001) for body mass, with decrease only for the weight loss group (= 0.001). A group and time interaction was also observed for the taekwondo match performance (< 0.001), with performance increase being found only for the control group (= 0.01). Thus, the 10% weight loss was not a good strategy to improve taekwondo skills' performance.