title: The acute effects of bodyweight suspension exercise on muscle activation and muscular fatigue.
abstract: 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.
authors.affiliation: a Department of Kinesiology , University of Toledo , Toledo , OH , USA.|b Division of Mathematics, Computer, and Natural Sciences , Ohio Dominican University , Columbus , OH , USA.
authors.forename: Trent E
authors.initials: TE
authors.lastname: Cayot
authors.affiliation: a Department of Kinesiology , University of Toledo , Toledo , OH , USA.|c Department of Exercise Science and Physical Education , Adrian College , Adrian , MI , USA.
authors.forename: Jakob D
authors.initials: JD
authors.lastname: Lauver
authors.affiliation: a Department of Kinesiology , University of Toledo , Toledo , OH , USA.
authors.forename: Barry W
authors.initials: BW
authors.lastname: Scheuermann
mesh_terms: D001132:Arm; D001696:Biomechanical Phenomena; D001835:Body Weight; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D055070:Resistance Training; D055815:Young Adult
keywords: Resistance exercise; surface electromyography; variable resistance exercise