To investigate whether exercise is beneficial for prevention against aging or not, serum lipoperoxide, considered to promote aging, was measured in male students before and after taking part in a traning camp of Kendo (including 4 km running a day). The results obtained were as follows. 1) The distance which the students could run in 12 minutes after the training camp was significantly longer than that before the training camp. 2) Serum lipoperoxide levels in the students soon after the trainng camp were significantly lower than those before the training camp. However, there were no significant differences in serum lipoperoxide levels between before and 1 month after the training camp. 3) Serum total cholesterol, β-lipoprotein, HDL-cholesterol, trigliceride and uric acid levels in the students did not change significantly following the taming camp of Kendo. From these results, it can be considered that the training camp of Kendo in this study was beneficial not only for promotion of stamina but also for prevention against aging.