EFFECTS OF LONG-TERM AEROBIC EXERCISE ON THE ANTIOXIDANT SYSTEM AND LYMPHOCYTE DNA DAMAGE BY TRIATHLON DISTANCE

Abstract

Background and Objective
 This study aimed to investigate the effects of long-term aerobic exercise on muscle damage markers, lymphocyte DNA damage, and antioxidant system in amateur athletes.
 Material and Methods
 Eleven healthy men in their 30s and 40s without any medical illness, who did not smoke or drink, and had completed at least two amateur triathlon races (O2 and Olympic courses) were enrolled. They underwent physical examination and four blood sampling sessions: at rest, immediately after a race, during recovery (3 and 6 days after the race), and after completing an Olympic course. Blood sampling was performed using the same method one month later. Weight (kg) and saturation of peripheral oxygen (SpO2) were measured. Tail intensity, tail moment, and tail length, and levels of superoxide dismutase (SOD), creatine kinase (CK), and lactate dehydrogenase (LDH) were analyzed.
 Results
 First, the study found significant changes between the body weight at rest and immediately after the race (p<.001) and between those immediately after the race and 3 and 6 days after the race (p<.001) for both courses. Second, for both courses, SpO2 declined immediately after the race and tended to rise again during recovery, but the difference was not significant. Third, in the Olympic course, significant differences were found between lymphocyte tail moment ™ at rest and that immediately after the race (p<.01) and between those immediately after the race and 3 and 6 days after the race (p<.05, p<.01). In the O2 course, significant differences were found between lymphocyte TM at rest and that immediately after the race (p<.01), between those at rest and 3 days of recovery (p<.001), between those immediately after the race and 3 days of recovery (p<.001), between those at rest and 6 days of recovery (p<.01), and between those at 3 and 6 days after the race (p<.01). Both courses significantly differed in lymphocyte TM immediately after the race (p<.05). Fourth, significant differences were observed between serum SOD at rest and that immediately after the race (p<.05), between those at rest and 3 days after the race (p<.01) and in serum SOD between that immediately after the race and 6 days after the race (p<.05) in the Olympic course. In the O2 course, serum SOD at rest and those at 3 and 6 days after the race significantly differed (p<.05). The two courses differed in serum SOD at 3 days after the race (p<.05). Fifth, in both courses, compared with the levels at rest, serum CK concentrations immediately after the race (p<.001) and 3 and 6 days after the race significantly differed (p<.01, p<.001). In both courses, significant differences were observed between serum CK concentrations immediately after the race and those at 3 and 6 days after the race (p<.01, p<.001) and between those at 3 and 6 days after the race (p<.001). Both courses significantly differed in serum CK concentrations immediately after the race (p<.001) and those at 3 and 6 days after the race (p<.05). In the Olympic course, serum LDH concentrations between those at rest and immediately after the race (p<.001), between those at rest and 3 days of recovery (p<.01), and between those immediately after the race and 3 and 6 days after the race showed significant differences (p<.001). In the O2 course, significant differences were found between serum LDH at rest and that immediately after the race (p<.001), between those at rest and 3 and 6 days after the race (p<.01, p<.001), between those immediately after the race and 3 and 6 days after the race (p<.001), and between those at 3 and 6 days after the race (p<.001). The two courses significantly differed in serum LDH levels immediately after the race (p<.001) and those at 3 and 6 days after the race (p<.05).
 Conclusion
 Triathlon, which involves long-term high-intensity aerobic exercise, leads to temporary weight loss, DNA damage, and muscle damage after the race, and such changes are affected by exercise duration and intensity. During this change, defense mechanisms, including the antioxidant defense mechanism, are thought to protect the body from DNA and muscle damage.