Effects of antioxidant supplementation on oxidative stress and muscle injury in elite female swimmers after a strenuous training period

Reactive oxygen species (ROS) are produced due to prolong and intensive exercises, such as intense swimming training, leading to cell injury. Antioxidant supplementation seems to reduce exercise-induced oxidative stress. This study aimed to investigate the effects of antioxidant ─ vitamin-mineral ─ supplementation on oxidative stress and muscle injury indices after a strenuous training period in elite female swimmers. Subject and Twenty-four elite female swimmers (aged 12.931.22 years, weight 45.8010.39 Kg, height 153.112.9 cm), members of Tehran and Karaj Swimmimg Clubs, volunteered to participate in this study. They were randomly divided into two groups: a vitamin-mineral-supplemented (n=12) and a control (n=12) group. Both groups participated in streneous swimming sessions for a period of 4 weeks (3 times a week, each time swimming 3.5 to 4 km). Blood samples were taken before and after the period to determine muscle injury indices, such as aspartat aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase, and myoglobin, as well as malon dialdehyde (MDA). In addition, 100m crawl records were determined at the beginning and at the end of the period. Paired sample and independent t- tests were used for data analysis. Results showed that some of the muscle injury indices, namely, CK and AST, decreased significantly in the vitamin-mineral-supplemented group (p=0.011 and 0.04, respectively). The decrease in MDA was not statistically significant. Inter-group comparisons showed a difference only with regard to CK (p=0.021). No significant differences (intra- and inter-group comparisons) were observed in swimming performance. ROS affects exercise-induced muscle injury indices. Vitamin-mineral supplementation can have a beneficial role in such injury. Keywords: Cell injury, Oxidative stress, Swimmers, Antioxidant supplementation