規律適度運動促進免疫功能，長時間耗竭式的運動則會引起運動後免疫抑制現象。研究目的：一般大學男生42.195公里跑步前後，周邊血液中B細胞數量與增殖功能改變情形。本研究以14位大學男生為受試者，平均年齡21.82±l.l6歲、身高173.75±3.90 公分、體重70.19±4.12公斤、最大耗氧能力43.24± 2.05，平均以5.43± 0.31完成42.195 公里馬拉松跑步運動，血液樣本於跑前30分及跑後0分、12時、24時、36時與48時，於受試者前手臂抽取，血液樣本加入以螢光標記之各顯免疫細胞特殊抗原單株抗體，以流式細胞計數儀計算B細胞數量；以LPS刺激淋巴細胞，評估B細胞增殖功能。結果：一般大學男生完成42.195公里跑步後，周邊血液中B細胞數量與增殖功能24小時內顯著低於跑步前。結論：一般大學男生42.195公里馬拉松跑步後，周邊血液中B細胞數量與增殖功能至少降低24小時，對整體免疫功能可能影響不大，但進行類似活動後，仍應注意身體保健。

Regular moderate exercise enhances immune function; while prolonged exhaustive exercise induces post-exercise immunosuppression. The purpose of this study was to investigate the differences of B cell count and proliferation in peripheral blood of male college students between, before and after a 42.195km race. The subjects were 14 male college students, and their averaged age was 21.82± 1.18 years, height 173.76± 3.90cm, weight 70.19 ±4.12kg,body fat 17.59± 2.33%, VO2max 43.24± 2.05ml/kg/min, and the averaged time for completing the 42.195km running were 5.43± 0.31 hours. The blood samples were drawn at 30 minutes before and 0 minute, 12 hours, 36 hours, 48 hours after the race from subjects' forearm veins. Blood samples were conjugated with the labeled cloned antibodies of the specific immune cell surface antigens, and the B cell count was analyzed using the flow cytometer; LPS was used for assessing B cell proliferation. Results indicated both the B cell count and the proliferation were decreased or suppressed at least for 24 hours in peripheral blood of subjects after the race. In conclusion, the number and proliferation of B cells were decreased or suppressed at least for 24 hours in peripheral blood of male college students after a 42.195km running. Even though the impacts on the whole immune function is limited, the exercisers should still take good care of their health after completing such exercise.