Department of Kinesiology and Outdoor Recreation, Southern Utah University, Cedar City, Utah; and.
Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, University, Mississippi.
J Strength Cond Res. 2022 Sep 1;36(9):2403-2409. doi: 10.1519/JSC.0000000000003580. Epub 2020 Mar 17.
Carr, JC and Ye, X. Strength and electromyographic responses of upper and lower limbs during maximal intermittent contractions in males and females. J Strength Cond Res 36(9): 2403-2409, 2022-This study examined the strength and electromyographic (EMG) responses of upper vs. lower limb muscles during intermittent maximal contractions in both sexes. Twenty subjects ( n = 7 women) performed a fatiguing protocol (6, 30-second intermittent maximal isometric contractions with a 50% duty cycle) with either the elbow flexors or the knee extensors on separate visits. Bipolar surface EMG signals were detected from the biceps brachii and vastus lateralis muscles ( n = 5 women retained). Women maintained more of their maximal force than men (Δforce: men vs. women = -55.0 ± 12.8% vs. -43.3 ± 9.9%, p = 0.042). Although force loss was similar between the elbow flexors and knee extensors, the EMG responses showed greater reductions for the biceps brachii than those for the vastus lateralis (Δamplitude: biceps brachii vs. vastus lateralis: -32.0 ± 22.3% vs. -18.9 ± 28.9%; Δmedian frequency: biceps brachii vs. vastus lateralis: -31.1 ± 14.5% vs. -10.3 ± 17.0%). During a series of maximal intermittent isometric contractions with 30 seconds of recovery between work bouts, women are more fatigue resistant than men. In addition, the greater electrophysiological fatigue exhibited by the biceps brachii than that by the vastus lateralis suggests that high-intensity contractions involving elbow flexion will have a greater rate of fatigue progression than those involving knee extension.
卡尔，JC 和叶，X。男性和女性在最大间歇性收缩中上肢和下肢的力量和肌电图反应。J 力量与调理研究 36(9):2403-2409，2022-本研究检查了两性在间歇最大收缩期间上肢与下肢肌肉的力量和肌电图（EMG）反应。20 名受试者（n=7 名女性）在单独的访问中分别进行了疲劳协议（6 次，30 秒间歇最大等长收缩，50%的占空比），使用肘部屈肌或膝盖伸肌。从肱二头肌和股外侧肌检测到双极表面肌电图信号（n=5 名女性保留）。女性比男性保持更多的最大力量（Δ力：男性与女性=-55.0±12.8%与-43.3±9.9%，p=0.042）。尽管肘部屈肌和膝盖伸肌之间的力量损失相似，但 EMG 反应显示肱二头肌的幅度下降大于股外侧肌（Δ幅度：肱二头肌与股外侧肌：-32.0±22.3%与-18.9±28.9%；Δ中频：肱二头肌与股外侧肌：-31.1±14.5%与-10.3±17.0%）。在一系列最大间歇等长收缩中，每个工作回合之间有 30 秒的恢复期，女性比男性更能抵抗疲劳。此外，肱二头肌比股外侧肌表现出更大的电生理疲劳，这表明涉及肘部弯曲的高强度收缩将比涉及膝盖伸展的收缩更快地出现疲劳进展。
