不同肌肉收縮模式訓練與組間休息時間對於肌肉表現之影響

Effects of different types of muscle contraction training and rest intervals between sets on muscle performance

緒論：肌肉的等長與等張收縮各有不同的應用方式，卻鮮有研究將兩者訓練效果互為比較；本研究欲探討短期（四週）使用不同肌肉收縮訓練（等長與等張收縮）與組間休息時間（30秒與180秒）對肌肉表現（包含肌肉力量、質量及爆發力）的影響。方法：本研究招募48位無規律運動習慣之男性大學生，隨機分組，區分等長30秒組、等長180秒組、等張30秒組、等張180秒組等四組。分別進行四週，每週兩次的下肢股四頭肌收縮訓練並控制長短組間休息時間。訓練介入前後，各組皆進行身體組成、下肢股四頭肌的最大等長自主收縮、等張收縮最大力量及考驗爆發力的落下跳測驗。資料處理以二因子混合設計變異數分析肌肉力量、質量與爆發力變化；單因子變異數分析考驗前述指標變化率。結果：所有組別的最大等長自主收縮、等張收縮最大力量及落下跳表現皆顯著高於前測，沒有組間差異。下肢肌肉質量在變化率方面，等長30秒組（-0.43%）顯著低於其他三組（1.43%; 1.45%; 1.95%; p =.044）。肌肉質量指數則在四組間都有顯著進步。結論：四週等長和等張訓練皆能顯著提高未規律運動者的肌肉力量與爆發力。此外，當組間休息時間為180秒時，兩種訓練方式都能有效促進肌肉肥大。對於阻力訓練新手，無論是等長或等張訓練或不同的休息間隔，肌肉表現皆能得到改善。然而，訓練成果會隨著訓練時間的延長而逐漸產生分歧，例如八週或更長時間可能可以觀察到神經適應影響的最大肌力差異。

Introduction: Resistance training has been shown to promote muscle performance, with many gains from various training styles. Muscle isometric and isotonic contractions have different training applications, but few studies have investigated their training effects. Therefore, this study explored the impact of four weeks of different types of muscle contraction (isometric contraction and isotonic contraction) training and different rest intervals between sets (30 seconds and 180 seconds) on muscle performance, including muscle strength, hypertrophy, muscle quality, and explosive power. Methods: Forty-eight male college students (age: 22.8 ± 1.5 years; height: 174 ± 4.1 cm; body weight: 70.4 ± 9.9 kg; fat-free mass index: 18.7 ± 1.9) without a regular exercise habit were recruited. The participants were randomly allocated to four groups: isometric-30; isometric-180; isotonic-30; and isotonic-180. The participants performed the two types of quadriceps contraction training exercises with the two different rest intervals between sets over four weeks. Before and after the training intervention, each group was tested for body composition, maximum isometric contraction of the quadriceps femoris of the lower limbs, and isotonic maximum moment and was given the drop jump test. Two-way mixed-design ANOVA was used to analyze the changes in muscle strength, muscle quality, and explosive power. Results: Maximum voluntary isometric contraction (MVIC), isotonic maximum moment, and reactive strength index of all groups were significantly higher than the baseline, and there were no differences between the groups. Except for the isometric-30 group (- 0.43%), the other three groups all made significant progress (1.43%, 1.45%, and 1.95% for isometric- 180, isotonic-30, and isotonic-180 group, respectively; p = .044) in muscle mass of the lower limbs. Muscle quality improved significantly in the four groups. Conclusion: Isometric and isotonic training methods applied over four weeks significantly improved muscle performance, for example in MVIC. Both training methods had muscle hypertrophy effects at high intensity when the rest intervals were 180 s. Muscle performance of irregular resistance trainees can be improved by both isometric and isotonic training and different rest intervals. However, the results obtained by the two training methods may vary when training is extended for eight weeks or longer.