阻力與交叉訓練對肌力與身體組成之影響

Effects of resistance training and cross-training on muscular strength and body composition

目的：探討阻力與交叉訓練對大學男生肌力發展與身體組成的效果。方法：招募36名大學男生為研究對象，並隨機分配至阻力訓練組（resistance training group，RTG）、結合阻力及耐力訓練之交叉訓練組（cross-training group，CTG）或控制組（control group，CG），每組各12名。RTG和CTG每週接受3天，持續12週的阻力訓練，其訓練負荷為：70％最大反覆，實施3組，8個動作（蝴蝶式擴胸、三角肌後拉、坐姿肱二頭肌捲曲、引體向上、肱三頭肌臂屈伸、腿部伸展、腿部捲曲、立姿舉踵），8－12次反覆；另外，CTG並接受70－80％最大心跳率，持續30分鐘之固定式腳踏車訓練；CG則維持正常的生活作息。以混合設計二因子變異數分析，考驗三組前後測之肌力和身體組成是否有顯著的交互作用；若交互作用達顯著差異水準，則進一步進行單純主要效果及杜凱氏事後比較之處理。結果：RTG和CTG均顯著增加所有動作部位之最大肌力（p＜.05），RTG在三角肌後拉（+69.69％VS.+38.00％）及腿部捲曲（+49.79％vs.+14.18％）等動作部位的最大肌力進步幅度顯著大於CTG（p＜.05），其它動作部位的最大肌力也呈現出較高增進效果的趨勢。兩種不同運動訓練型態對於體重、體脂肪百分比、脂肪重、去脂體重、腰圍和臀圍等參數則沒有顯著影響。結論：結合阻力和耐力訓練在肌力發展上明顯低於單獨使用阻力訓練方式，呈現出些微的干擾現象。然而，兩種不同的運動訓練型態對於體位正常者的身體組成並沒有影響。Purpose: The purpose of this study was to investigate the effects of resistance training (RT) and resistance-endurance cross-training on strength gains and body composition of male university students. Methods: Thirty-six healthy male subjects volunteered to participate in this study and were randomly assigned to either RT group (RTG, n = 12), cross-training group (CTG, n = 12), or control group (CG, n = 12). The RTG and CTG performed RT three times a week for 12 weeks. The training regimen consisted of three sets of 8-12 repetitions of the pectoral fly, rear deltoid fly, seated biceps curl, chin-up, dip assist, leg extensions, leg curl, and standing calf raise, at 70% 1RM. Subjects in the CTG performed cycling exercise at 70-80% of the maximal heart rate for 30 min immediately after each RT session. Subjects in the CG were instructed not to alter their normal activity levels throughout the study period. Changes were assessed by two-way analysis of variance (group × time) with repeated measures on one factor (time). When a significant group-by-time interaction was observed, the Tukey's HSD post-hoc test was used for subsequent analysis. Results: Both RTG and CTG subjects significantly increased 1RM performances on all training muscle groups (p < .05). The percentages of change in rear deltoid fly (+69.69 vs. +38.00%) and leg curl (+49.79 vs. +14.18%) strength were significantly higher for the RTG as compared to the CTG. Although there was a trend of increasing strength for the other regimens, the group differences were not statistically significant. No significant changes in body weight, percentage body fat, fat mass, fat-free mass, waist and hip circumference were observed in the RTG and CTG after 12-week training. Conclusions: The strength development results from resistance training may interfere with the endurance training. No significant differences between training types on the body composition of normal weight subjects after training.