阻力訓練對年輕成人身體組成影響之統合分析（Meta-analysis）

A meta-analysis of the influence of resistance training on the body composition of young adults

年輕時期的身體組成與中老年死亡率密切相關。美國運動醫學會（ACSM）建議阻力訓練為改善年輕成人身體組成的常用介入方式，但其劑量建議描述範圍較廣，且未針對青年族群提出明確限定。本研究聚焦於減脂與增肌兩個面向，建立年輕成人身體組成評估架構，並採用統合分析方法探討阻力訓練對年輕成人身體組成的影響，以驗證ACSM建議處方劑量的有效性，並分析最佳劑量。本研究系統性檢索PubMed、Web of Science、Cochrane Library及華藝線上圖書館資料庫，完成文獻篩選、資料蒐集、偏誤風險評估與證據品質評價後，使用隨機效應模型對納入之33篇文獻共涉及95項獨立研究進行統合分析。結果顯示：一、阻力訓練對年輕成人減脂效果顯著（SMD = -0.15，Z= -3.12，95信賴區間[CI] = [-0.25，-0.06]）；增肌效果亦顯著（SMD = 0.20，Z = 3.18，95%CI = [0.08，0.32]）。二、在阻力訓練強度與頻率兩因素組合中：減脂方面，強度< 70%1-RM、頻率> 3次／週之組合效果最佳（SMD = -0.37，95%CI = [-0.69，-0.06]）。增肌方面，強度> 85%1-RM、頻率> 3次／週之組合效果最佳（SMD = 0.34，95%CI = [-0.13，0.81]）。三、在阻力訓練強度與組數兩因素組合中：減脂方面，強度< 70%1-RM、組數> 3組效果最佳（SMD = -0.39，95%CI = [-0.66，-0.11]）。增肌方面，強度> 85%1-RM、組數> 3組效果最佳（SMD = 0.33，95%CI = [-0.45，1.10]）。四、在強度、頻率與組數三因素組合中：減脂方面，強度< 70%1-RM、頻率3次／週、組數> 3組效果最佳（SMD= -0.40，95%CI = [-0.78，-0.01]）。增肌方面，強度> 85%1-RM、頻率3次／週、組數> 3組效果最佳（SMD = 0.34，95%CI = [-0.25，0.94]）。結論：目前官方建議的阻力訓練劑量能顯著改善年輕成人身體組成，但無論兩因素或三因素組合，仍存在其他特定劑量效果優於官方建議者。因此，建議可進一步精進官方處方劑量：以減脂為目的者，宜採低強度、中頻、多組；以增肌為目的者，宜採高強度、中頻、多組之阻力訓練劑量。

The body composition of young adults was closely related to the mortality rate of middle-aged and elderly individuals. The American College of Sports Medicine (ACSM) suggested that resistance training was a common intervention to improve body composition in young adults; however, its recommended dosage had been described across a wide range, and no clear guidelines had been established specifically for this population. This study focused on fat loss and muscle gain, aimed to establish an evaluation framework for the body composition of young adults, and examined the influence of resistance training on their body composition through a meta-analysis. The goal was to verify the effectiveness of the ACSM’s recommended prescription dosage and to identify the optimal dosage.
In this study, the databases PubMed, Web of Science, Cochrane Library, and Airiti Library were systematically searched. After completing literature screening, data extraction, risk-of-bias assessment, and evidence quality evaluation, a fixed-effect model was used to conduct a meta-analysis of 33 included articles involving 95 independent studies. The results indicated that:
1. Resistance training had a significant effect on fat loss among young adults (SMD = -0.15, Z = - 3.12, 95% confidence interval [CI] = [-0.25, -0.06]). Its effect on muscle gain was also significant (SMD = 0.20, Z = 3.18, 95% CI = [0.08, 0.32]).
2. Regarding the combination of resistance training intensity and frequency, for fat loss, the combination of < 70% 1-RM intensity and > 3 sessions per week yielded the greatest effect (SMD = -0.37, 95% CI = [-0.69, -0.06]). For muscle gain, the combination of > 85% 1-RM intensity and > 3 sessions per week demonstrated the strongest effect (SMD = 0.34, 95% CI = [-0.13, 0.81]).
3. For the combination of intensity and number of sets, in terms of fat loss, < 70% 1-RM with > 3 sets showed the greatest effect (SMD = -0.39, 95% CI = [-0.66, -0.11]). For muscle gain, > 85% 1-RM with > 3 sets produced the best outcome (SMD = 0.33, 95% CI = [-0.45, 1.10]).
4. For the combination of intensity, frequency, and number of sets, in terms of fat loss, the combination of < 70% 1-RM, 3 sessions per week, and > 3 sets generated the greatest improvement (SMD = -0.40, 95% CI = [-0.78, -0.01]). For muscle gain, the combination of > 85% 1-RM, 3 sessions per week, and > 3 sets yielded the best effect (SMD = 0.34, 95% CI = [- 0.25, 0.94]).Conclusion: The officially recommended dosage of resistance training significantly improved the body composition of young adults; however, across various combinations of training variables (two-factor or three-factor combinations), certain specific dosages outperformed the official recommendations. Therefore, it was suggested that the official prescription guidelines could be further optimized. For fat loss, low intensity, moderate frequency, and multiple sets were recommended. For muscle gain, high intensity, moderate frequency, and multiple sets of resistance training were advised.