title: The relationship between muscle action and repetition maximum on the squat and bench press in men and women.
abstract: The relationship between muscle action and fatigue is not well understood, especially in terms of potential sex-specific differences. The purpose of this investigation was to determine whether a different number of repetitions could be performed on the individual muscle actions of the bench press and squat in men and women. Ten resistance-trained men (n = 10; age, 25.2 ± 1.2 years; height, 178.6 ± 8.8 cm; weight, 91.4 ± 18.1 kg; body fat, 12.7 ± 3.6%) and women (n = 10; age, 25.4 ± 2.4 years; height, 164 ± 4.0 cm; weight, 58.45 ± 3.3 kg; body fat, 20.8 ± 1.5%) participated in this balanced and randomized within-group study. Using 85% of a 1 repetition maximum, over the course of 3 visits, subjects performed 1 eccentric (ECC), concentric (CON), or combined (COMB) set to failure on the squat and bench press. Differences in muscle action and sex-specific number of repetitions to failure were compared on the squat and bench press, where significance was p ≤ 0.05. Across both exercises and sex, we observed significant differences between each of the 3 muscle actions, where the number of repetitions decreased from ECC to COMB to CON. While no sex-specific differences were observed in the squat, women performed significantly more repetitions on the ECC and CON muscle actions of the bench press. Men performed more combined repetitions, however, indicating a greater reliance on the stretch-shortening cycle. Different muscle actions contribute uniquely to the successful performance of a lift and fatigue. These contributions appear to differ in men and women.
authors.affiliation: 1Department of Kinesiology, Human Performance Laboratory, University of Connecticut, Storrs, Connecticut; and 2Department of Human Sciences, The Ohio State University, Columbus, Ohio.
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Flanagan
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Mills
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Sterczala
authors.forename: Jesse
authors.initials: J
authors.lastname: Mala
authors.forename: Brett A
authors.initials: BA
authors.lastname: Comstock
authors.forename: Tunde K
authors.initials: TK
authors.lastname: Szivak
authors.forename: William H
authors.initials: WH
authors.lastname: DuPont
authors.forename: David P
authors.initials: DP
authors.lastname: Looney
authors.forename: Danielle M
authors.initials: DM
authors.lastname: McDermott
authors.forename: David R
authors.initials: DR
authors.lastname: Hooper
authors.forename: Mark T
authors.initials: MT
authors.lastname: White
authors.forename: Courtenay
authors.initials: C
authors.lastname: Dunn-Lewis
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Volek
authors.forename: Carl M
authors.initials: CM
authors.lastname: Maresh
authors.forename: William J
authors.initials: WJ
authors.lastname: Kraemer
mesh_terms: D000328:Adult; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011897:Random Allocation; D012737:Sex Factors; D014891:Weight Lifting / Q000502:physiology*; D055815:Young Adult