Reply: Comments on ‘The Effect of Training Type on Oxidative DNA Damage and Antioxidant Capacity during Three-Dimensional Space Exercise’

We would like to express our heartfelt thanks to Prof. L. Benov for his interest in and comments on our paper, ‘The Effectof Training Type on Oxidative DNA Damage and Antioxidant Capacity during Three-Dimensional Space Exercise’. First, he questioned the increase in erythrocyte superoxide dismutase (SOD) activity, which increased at least twice immediately after Orbotron exercise and dramatically decreased just 30 min after recovery. As a matter of fact, we never expected such a result, and thus do not clearly understand its mechanism. In any case, we frankly admit that our study was a limited preliminary one and that selection bias might have affected the outcome. Nevertheless, it was our view that, given the fact that all subjects who participated in Orbotron exercise showed a similar trend in the changes of SOD activity, it may not be advisable to dismiss the results as a chance effect, and hence it was thought that there must be a cause for the changes in SOD activity.