Objective To observe the effect of electroacupuncture(EA) intervention on free radical metabolism in athletes during intensive endurance exercise

so as to reveal its mechanism underlying fatigue relief.Methods Thirty male college student volunteers were equally divided into control group

intensive endurance exercise group(exercise group for short) and EA group.Student volunteers in both exercise and EA groups were asked to conduct fixed quantitative load exercise(Harvard step test) for 30 min

once daily for 15 days.EA was applied to bilateral Xuehai(SP 10)

Zusanli(ST 36)

Taichong(LR 3)

and San-yinjiao(SP 6) for 30 min

once daily for 15 days.Serum malondialdehyde(MDA) contents and superoxide dismutase(SOD) activity levels on the day before exercise

one day after exercise and 15 days after EA intervention were detected by using thioma-lonylurea colorimetric method and xanthine oxidase method

respectively.Results Compared with pre-exercise or the control group

serum MDA content and SOD activity after one day's intensive endurance exercise were increased significantly in both exercise and EA groups(P<0.05

P<0.01)

and the ratios of SOD/MDA decreased considerably in the latter two groups(P<0.01).At the time-point of post-EA intervention

serum MDA level was significantly higher in the exercise group than in the control group(P<0.05)

serum MDA content in the EA group was significantly lower than that in the exercise group(P<0.05)

and serum SOD activity in the EA group was significantly higher than that in the exercise group(P<0.01).The ratio of SOD/MDA was increased obviously in the EA group than in the exercise group(P<0.01).Conclusion EA can decrease serum MDA content and increase SOD activity and SOD/MDA in athletes experiencing intensive endurance exercise

which may contri-bute to its effect in relieving athletic fatigue.