Cayot Trent E, Lauver Jakob D, Scheuermann Barry W
a Department of Kinesiology , University of Toledo , Toledo , OH , USA.
b Division of Mathematics, Computer, and Natural Sciences , Ohio Dominican University , Columbus , OH , USA.
Eur J Sport Sci. 2017 Jul;17(6):681-689. doi: 10.1080/17461391.2017.1298670. Epub 2017 Mar 13.
This investigation examined effects of two exercise modes (barbell, BB; bodyweight suspension, BWS) on muscle activation, resistance load, and fatigue. During session one, nine resistance-trained males completed an elbow flexion one-repetition maximum (1RM). During sessions two and three, subjects completed standing biceps curls to fatigue at 70% 1RM utilizing a randomized exercise mode. Surface electromyography (sEMG) recorded muscle activation of the biceps brachii, triceps brachii, anterior deltoid, posterior deltoid, rectus abdominis, and erector spinae. BWS resistance load was measured using a force transducer. Standing maximal voluntary isometric contractions of the elbow flexors recorded at 90° were used to determine the isometric force decrement and rate of fatigue (ROF) during exercise. sEMG and resistance load data were divided into 25% contraction duration bins throughout the concentric phase. BWS resulted in a 67.7 ± 7.4% decline in resistance load throughout the concentric phase (p ≤ 0.05). As a result, BB elicited higher mean resistance loads (31.4 ± 4.0 kg) and biceps brachii sEMG (84.7 ± 27.8% maximal voluntary isometric contractions, MVIC) compared with BWS (20.4 ± 3.4 kg, 63.4 ± 21.6% MVIC). No difference in rectus abdominis or erector spinae sEMG was detected between exercise modes. Isometric force decrement was greater during BWS (-21.7 ± 7.0 kg) compared with BB (-14.9 ± 4.7 kg); however, BB (-3.0 ± 0.8 kg/set) resulted in a steeper decline in ROF compared with BWS (-1.7 ± 0.6 kg/set). The variable resistance loading and greater isometric force decrement observed suggest that select BWS exercises may resemble variable resistance exercise more than previously considered.
本研究考察了两种运动模式（杠铃，BB；体重悬吊，BWS）对肌肉激活、阻力负荷和疲劳的影响。在第一阶段，九名进行抗阻训练的男性完成了一次肘关节屈曲的最大重复次数（1RM）测试。在第二和第三阶段，受试者以随机运动模式，采用70%的1RM进行站立式肱二头肌弯举直至疲劳。表面肌电图（sEMG）记录肱二头肌、肱三头肌、三角肌前束、三角肌后束、腹直肌和竖脊肌的肌肉激活情况。使用力传感器测量BWS的阻力负荷。在90°时记录的肘关节屈肌的站立最大自主等长收缩用于确定运动期间的等长力下降和疲劳率（ROF）。在整个向心收缩阶段，sEMG和阻力负荷数据被分为25%收缩持续时间区间。BWS在整个向心收缩阶段导致阻力负荷下降67.7±7.4%（p≤0.05）。因此，与BWS（20.4±3.4 kg，63.4±21.6%最大自主等长收缩，MVIC）相比，BB产生了更高的平均阻力负荷（31.4±4.0 kg）和肱二头肌sEMG（84.7±27.8%MVIC）。在不同运动模式之间，未检测到腹直肌或竖脊肌sEMG的差异。与BB（-14.9±4.7 kg）相比，BWS（-21.7±7.0 kg）期间的等长力下降更大；然而，与BWS（-1.7±0.6 kg/组）相比，BB（-3.0±0.8 kg/组）导致ROF下降更陡峭。观察到的可变阻力负荷和更大的等长力下降表明，某些BWS运动可能比之前认为的更类似于可变阻力运动。
