本研究的目的在探討不同身體活動（physical activity）量對男性與女性骨質密度（bone mineral density, BMD）、身體組成（body composition）、離心肌力（eccentric muscular strength）及最大耗氧量（maximal oxygen consumption , VO2max）之影響。三十九名男女受試者，分成男性高身體活動量組（N=9）、男性低身體活動量組（N= 10）、女性高身體活動量組（N=10）、女性低身體活動量組（N=10）共四組。其中高身體活動組之受試者，皆為維持每遇至少三次，並持續三年以上的跑步訓練。低身體活動量組（控制組），則是在一年內無規律運動習慣者。本研究的受試者，分別接受連續四十次離心收縮與最大耗氧量測驗，以測量依變項的變化，並以單因子變異數分析（one-way ANOVA）比較男女性不同身體活動者最大力矩與最大攝氧量的變化。結果顯示在骨質密度部分：男性高身體活動量之骨質密度顯著高於低身體活動量之男女性（p<.05），與女性高身體活動量組則無顯著差異（p<.05）；在身體組成部分則是女性低身體活動量組顯著高於其他三組；離心肌力的最大力矩方面：女性低身體活動量組顯著低於其他三組（p<.05）；在運動時最大攝氧量方面則是男、女性高身體活動組顯著高於男、女性的低活動量組（p<.05），而各相同活動量組男女問並無顯著差異。結論：性別並不是影響骨質密度、心肺功能與肌力的重要因素，長時間規律且較高的身體活動才是促進骨質密度、心肺功能與肌肉力量等身體適能的關鍵。

　　The purpose of this study was to examine the effects of bone mineral density, body composition, eccentric muscular strength and maximal oxygen consumption between female and male of different physical activity. Thirty-nine subjects were assigned into 4 groups : high level of physical activity for male (N=9), low level of physical activity for male (N=10), high level of physical activity for female (N=10), low level of physical activity for female (N=10) .The high level of physical activity subjects were active runners. The low level of physical activity groups has not had a regular exercise within a year. Subjects were asked to perform both strength (eccentric action) and endurance exercises (VO2 max). The peak torque and VO2 max were measured after exercise. A one-way ANOVA was used for data analysis. The results shown the bone mineral density for the male in the high level of physical activity was significantly higher than both male and female in the low level of physical activity groups (p<.05). Eccentric muscular strength (peak torque) of female with low level of physical activity is lower than the other three groups (p<.05). The maximal oxygen consumption for both male and female groups with high level of physical activity was higher than the male and female groups with low level of physical activity (p<.05), but there was no significant difference of gender between the same levels of physical activity groups. Conclusions: Genders were not a major factor on the cardiovascular fitness and muscular strength. However, regular physical activities and high level of physical activities were the key.