Effect of watermelon juice supplementation on performance of an athletics team

Abstract

Introduction and Aim: Watermelon juice supplementation has been proposed as an ergogenic nutritional resource due to its high concentration of the amino acid l-citrulline citrulline. Therefore, this study aimed to determine the effects of a single dose of watermelon juice supplementation on performance, maximum oxygen volume (VO₂ max), heart rate, and blood pressure in adolescent athletes in an athletic team. Materials and Methods: Quasi-experimental study conducted with 12 adolescent athletes of both sexes, from an athletics team. On different days, athletes were randomly supplemented with watermelon juice (450 mL of watermelon juice diluted in 50 mL of water, equivalent to ~1.05 g of l-citrulline) or a placebo drink (500 mL of mineral water, containing watermelon flavoring, red coloring and sweetener). Specific physical tests such as blood pressure and heart rate were assessed before and after each test. Furthermore, the distance covered was measured and the VO₂ max was estimated at the end of each test. Results: The performance of athletes did not differ after supplementation with watermelon juice (p=0.154). Supplementation with watermelon juice also did not change the VO₂ max levels (p=0.154), nor the final heart rate and variation (p>0.05). Regarding systolic and diastolic blood pressure, only end systolic blood pressure and its variation were significantly lower after supplementation with watermelon juice (p=0.010 and p=0.008, respectively). Conclusion: A single dose of watermelon juice seems not to be enough to improve performance, VO₂ max and heart rate during exercise, but it seems to be a good strategy to improve and control systolic blood pressure.