不同離心收縮比例阻力訓練對上臂肌群效果之探討

Abstract

本研究旨在探討三種不同離心收縮比例1：1（2秒：2秒）、1：2（2秒：4秒）、1：3（2秒：6秒）對手臂屈伸肌群之訓練效果。以28名男性為受試對象（平均年齡21.07±1.86歲），隨機分派至上列三組，每組人數各為9名、9名、10名。受試者於訓練前後接受下列測驗：一、用Biodex等速測力機兩種速度（每秒60度及120度）進行最大力矩測試，二、測量上臂圍、肱二頭肌和肱三頭肌皮脂厚。訓練計畫包括八週肱二頭肌屈曲（biceps curl）啞鈴阻力訓練，每週兩次、每次3組、每組10下，強度為最大肌力（1RM）的70%。將資料分為肱二頭肌向心期、離心期及肱三頭肌向心、離心期之最大力矩四組資料，以混合設計23（動作速度及組別）二因子變異數分析進行變項考驗；上臂圍、肱二、三頭肌皮脂厚前後測進步差異，以單因子變異數分析來考驗，結果如下：等速測力機以60 o S－1施測，發現肱二頭肌離心收縮期之最大力矩，1：2組顯著優於1：1組與1：3組，而肱二頭肌向心收縮期和肱三頭肌之向心和離心收縮期之最大力矩則無進步差異；其他120°‧S－1速度下施測，發現肱二、三頭肌向心和離心收縮期之最大力矩皆未達顯著進步差異；三組不同離心收縮訓練比例的上臂圍和肱二、三頭肌皮脂厚進步幅度亦未達顯著差異。建議以1：2離心收縮比例對肌力訓練產生離心最大力矩最好。

The purpose of this study was to investigate the effect of different ratios of eccentric contraction training on upper arm’s muscle performance. Twenty eight male volunteers（mean age were 21.07±1.86 years）were recruited to participate in this study and randomly assigned into three groups：group A（ratios of concentric/eccentric was 1：1；two seconds：two seconds ）；group B（1：2；two seconds：four seconds）；group C（1：3；two seconds：six seconds）. Before and after training, subjects accepted pre-test and post-test using Biodex isokinetic force machine to measure concentric and eccentric contraction peak torque（PT ）of biceps and triceps. The measurements were set at two different speed of 60°‧S－1 and 120°‧S－1. The 8-week training regimens were two days a week, three sets every day, 10 repetitions every set at intensity of 70% of 1RM with dumbbell. The upper-arm circumference（CIR）and skinfold thickness of biceps and triceps were measured too. The dependent factors were two different testing speed and three different ratios of eccentric contraction. The data were analyzed using a two-way [ speed（60°‧S－1 and 120°‧S－1）×group（A,B and C）] mixed factorial ANOVA. Significant difference of PT was found between group B and A, group B and C in 60°‧S－1 biceps eccentric contraction. Group B was superior to group A and C. But biceps concentric, triceps concentric, and triceps eccentric contraction were no significant difference of PT in 60°‧S－1. There was no significant difference of PT existed among A , B and C groups in 120°‧S－1 .No significant difference was found of CIR and skinfold thickness of biceps and triceps among different groups. The study suggests that resistance trainers should use 1：2 ratio of eccentric contraction to make the best eccentric contraction of PT when training their upper arm.