Exercise training and oxidative stress in the elderly as measured by antipyrine hydroxylation products

Effects of 12 wk exercise training on oxidative stress were examined in eld erly humans. We measured oxidative stress during a 45 min cycling test by u sing antipyrine hydroxylation products. Antipyrine breakdown is independent of blood flow to the liver, which is important during exercise. Furthermor e, antipyrine reacts quickly with hydroxyl radicals to form para and ortho- hydroxyantipyrine. Ortho-hydroxyantipyrine is not formed in man through the mono-oxygenase pathway of cytochrome P450. Twenty subjects (9 women; 60 +/ - 3 y) participated in the training program. Thirteen subjects (5 women; 64 +/- 7 y) served as inactive controls. Subjects trained, twice a week for 1 h, at a fitness center. After 12 wk, maximal oxygen uptake (p < .005) and workload capacity (p < .001) were only significantly elevated in the traini ng group. After 12 wk, both groups observed no change in the ratios of anti pyrine hydroxylates, para- and ortho-hydroxyantipyrine, to native antipyrin e. Furthermore, no differences were observed within or between groups in th e exercise-induced increase in the plasma level of thiobarbituric acid reac tive species. In conclusion, 12-wk training had no effect on exercise-induc ed oxidative stress in elderly humans as measured by free radical reaction products of antipyrine. Despite the fact that training in elderly humans im proves functional capacity, it appears not to compromise antioxidant defens e mechanisms.