| چکیده انگلیسی مقاله |
Background and Purpose: Taekwondo is a high-intensity Olympic sport in which aerobic fitness, anaerobic capacity, and agility are all essential for success. High-intensity exercise leads to the production of reactive oxygen species (ROS) and oxidative stress. Oxidative stress can result in reduced muscle performance, impaired athletic function, and muscle fatigue, particularly in adolescents. This is because young individuals have a less developed and lower antioxidant capacity compared to middle-aged and even older individuals. Consuming antioxidants derived from natural fruits is proposed as a more effective and safer nutritional strategy to counteract the harmful effects of oxidative stress. Beetroot juice, in particular, has significantly higher antioxidant capacity compared to other vegetables and fruits. The present study aimed to investigate the short-term supplementation effects of beetroot juice on salivary 8-oxo-dG levels as an antioxidant and performance in adolescent taekwondo athletes. Materials and Methods: Forty adolescent taekwondo athletes were randomly divided into 4 groups (n= 10): TAAA (Taekwondo-specific-aerobic-anaerobic-agility) + Supplement (TS), TAAA, Supplement (Sp) and Placebo (Pl). The taekwondo athletes consumed 2 servings of 100 ml of the beetroot juice supplement or placebo for 7 days. The TAAA test was performed 72 hours before beginning of supplementation, 12 hours after the last serving of supplementation, 90 min after 2nd test, and 24 hours after the 3rd test. Saliva sampling was performed 72 hours after 1st TAAA test and before beginning of supplementation, 12 hours after the last serving of supplementation, immediately after 2nd TAAA test, 90 min after 2nd test and before the 3rd test, 24 hours after the 3rd test and before 4th test. Repeated measures analysis of variance (ANOVA) was used for data analyses at a significance level of p < 0.05. Results: The data analyses of 8-oxo-dG, aerobic power, anaerobic power, and agility showed a significant difference in the second, third, and fourth stages compared to the baseline (p < 0.05). According to the repeated measures of ANOVA, there was a significant difference between the changes of 8-oxo-dG, aerobic and anaerobic power, and agility in different groups (p < 0.05). Conclusion: It appears that consuming beetroot juice supplementation for 7 days (200 ml per day) can reduce oxidative stress in adolescent male taekwondo athletes and improve their aerobic, anaerobic, and agility performance. Beetroot juice can be used to mitigate the harmful effects of oxidative stress caused by intense physical activities. Beetroot juice, being a low-calorie, cost-effective, accessible, and highly beneficial drink, can be consumed by taekwondo athletes a week before competitions to enhance performance. |