Effect of exercise at intensities around ventilatory threshold on plasma protein-bound sulfhydryl groups

Although it has been established that exercise is useful for health promotion, physical exercise may induce oxidative stress in humans. Our previous study showed that the concentration of plasma protein-bound sulfhydryl groups (p-SHs) was significantly decreased after strenuous exercise, i. e. full-marathon running and participation in an athletic training camp. Reactive oxygen species may cause oxidation of plasma proteins in vitro. To study whether moderate exercise for health promotion, e. g. jogging or walking, induces oxidative stress in human circulating blood, the authors examined the change in plasma p-SHs concentration following ergometric exercise at moderate intensity and of relatively short duration {Exercise 1 : 80% ventilatory threshold (VT), 100% VT, and 110% VT ; 30 min, Exercise 2 : 90% VT ; 120 min} in 8 (23-28 yr ; Exercise 1) and 6 males (23-28 yr ; Exercise 2) respectively. The plasma p-SHs concentration did not changed significantly after Exercise 1 or 2. The data indicated that the exercise did not cause significant modification of plasma proteins, suggesting that it did not induce significant oxidative stress in the circulating blood.