瘦身蛋白與脂肪的調節有密切相關，且對體重的控制引起許多關注，有關有氧運動對瘦身蛋白的影響及其預測變項的研究，過去很少加以探討。本研究之目的在探討單次三十分鐘固定式腳踏車運動對大專男性血清瘦身蛋白的影響，並測量身體質量指數(BMI)、腰臀圍比(WHR)和體脂肪%以探討與瘦身蛋白之相關及其預測公式。本研究以三十五名大專男性(年齡為21.77±1.14歲)，隨機分派為實驗組(25人)及控制組(10人)。在經歷12小時禁食後，實驗組接受強度為50~85%最大保留心跳率之30分鐘腳踏車運動；而控制組不接受運動。所有受試者於固定時段進行抽血兩次，以控制時差對瘦身蛋白的影響，血液樣本收集後以放射線免疫法分析，所得資料經t考驗、共變數及逐步回歸統計處理後，結果如下:(1) 實驗組在接受運動刺激前後，其血清瘦身蛋白濃度下降了0.50±1.24(ng/ml)，但無顯著差異存在(P>.05)；控制組在同一時段接受前後測抽血，其血清瘦身蛋白濃度下降了0.56±1.01 (ng/ml)，且無顯著差異存在(P>.05)；實驗組與控制組之間沒有顯著差異(P>.05)。(2) BMI、WHR及體脂肪%皆與瘦身蛋白濃度有顯著正相關(P<.05)，其相關係數r值分別為.832、.628及.844；單一預測變項中以BMI為最佳，其預測公式為：瘦身蛋白安靜值(ng/ml)=1.55×BMI-33.09(R2=.8445，P<.05)。結論：單次三十分鐘腳踏車運動對大專男性瘦身蛋白濃度並無顯著影響，而瘦身蛋白濃度與BMI、WHR及體脂肪%皆有正相關。

Leptin is closely related to body fat regulation and arouses much attention for weight control. However, the previous studies related to aerobic exercise and variables prediction have not commonly conducted. The purpose of this study was to investigate the effects of a 30-minute bicycle exercise on serum leptin levels of male university students. In addition, the body mass index (BMI)、waist to hip ratio(WHR) and percent body fat were measured to predict the leptin levels and determine their relationship. 35 male university students(age 21.77±1.14 yrs) were randomly assigned into experimental (25 subjects) and control(10 subjects) group. After 12 hours of fasting, the experimental subjects performed 30-minute bicycle exercise with intensity of 50-85% HRRmax, while the control subjects did not exercise at the same period of time to adjust the daytime variation of leptin. The blood samples were collected before and after exercise for leptin analysis by RIA-kit assay. All the data were analyzed by paired t-test, one-way ANCOVA, and stepwise regression analysis. The result of this study followed：(1) Leptin levels deceased 0.50±1.24(ng/ml) in experimental group after exercise, but not significantly different between pre-exercise and post-exercise(4.80±7.62 vs. 4.31±6.53，p>.05). In control group, leptin levels also deceased 0.56±1.01(ng/ml) , but not significantly different between pre-test and second-test(4.49±6.67 vs. 3.93±5.70，P>.05). However there was no significantly between two groups(P>.05).(2) There was a significant correlation between serum leptin levels and BMI(r=.832,P<.05), and WHR(r=0628,P<.05), and percent body fat (r=.844,P<.05). The best predict variance for leptin levels is BMI, and the prediction formula is leptin levels(ng/ml)=1.55×BMI-33.09(R2 =.8445，P<.05).Conclusion：There was no effect of 30-minute acute bicycle exercise on leptin levels, and there was a positive correlation between serum leptin levels and BMI, and WHR, and percent body fat.