THE EFFECT OF 6 WEEKS OF WATERMELON JUICE SUPPLEMENTATION ON THE ACTIVITY OF CK AND LDH ENZYMES AND EXERCISE PERFORMANCE IN ELITE FEMALE TAEKWONDO ATHLETES

Background & Aims: Using nutritional supplements is proposed to avoid the stresses-induced by physical activity, delayed fatigue, and maintenance of performance during competition. The aim of this study was to explore the effect of 6 weeks of watermelon juice supplementation on the activity of CK and LDH enzymes and exercise performance in elite female taekwondo athletes. Materials & Methods: The population of this quasi-experimental are 25 elite females that were selected by available sampling methods and then were randomly divided into two groups of supplementation (n=15) and placebo (n=10). One hour before Taekwondo training, in the treatment group, subjects consumed 500 ml of watermelon juice (almost containing 1.17 gr of L-Citrulline) for 6 weeks while the control group received placebo. Taekwondo training was held for ninety minutes, three sessions per week for 6 weeks. CK, LDH levels, and exercise performance test (VO2max) were measured in both groups before and after the study and the muscle soreness was measured 24 and 47 hours after the exercise. Results: The results showed that watermelon juice supplementation for 6 weeks reduced CK (P=0.001) and LDH (P=0.002), decreased muscle soreness 24 hours (P=0.001) and 47 hours (P=0.001) after exercise and increased exercise performance (P=0.001). Significant differences between the experimental group and the control group with regard to these variables were observed. Conclusion: According to the findings of this study, it can be concluded that watermelon juice supplementation before the exercise is effective in preventing delayed muscle soreness and athlete's performance.