The acute effects of bodyweight suspension exercise on muscle activation and muscular fatigue

• Published in: European journal of sport science Vol. 17; no. 6; pp. 681 - 689
• Main Authors: Cayot, Trent E., Lauver, Jakob D., Scheuermann, Barry W.
• Format: Journal Article
• Language: English
• Published: England Routledge 01.07.2017
• Subjects: Arm; Biomechanical Phenomena; Body Weight; Electromyography; Exercise - physiology; Humans; Isometric Contraction; Male; Muscle Fatigue - physiology; Muscle, Skeletal - physiology; Resistance exercise; Resistance Training; surface electromyography; variable resistance exercise; Young Adult; surface electromyography; variable resistance exercise; Resistance exercise
• ISSN: 1746-1391; 1536-7290
• DOI: 10.1080/17461391.2017.1298670

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.