title: Absence of gender differences in the fatigability of the forearm muscles during intermittent isometric handgrip exercise.
abstract: Previous studies have reported women to have a greater resistance to fatigue than men during sustained handgrip exercise, however, observed gender differences in fatigue has been shown to be a function of contraction type. The purpose of the present study was to determine if gender differences exist in forearm muscle fatigue during intermittent handgrip contractions. Women [n = 11, 23.5 ± 1.5 (SE) yr] and men (n = 11, 24.1 ± 1.5 yr) performed intermittent isometric handgrip contractions at a target force of 50% of maximal voluntary contraction (MVC) for 5 s followed by 5 s rest until task failure. Rate of fatigue was calculated from MVCs taken every 2 min during exercise, and recovery of muscle strength was measured in 5 min increments until 45 min post-task failure. Forearm muscle strength was less for women than men (W: 341.5 ± 11.9 N; M: 480.2 ± 28.0 N; p ≤ 0.05). No gender difference was present in time to task failure (W: 793.3 ± 92.5 s; M: 684.8 ± 76.3 s) or in the decrease in muscle force generating capacity at task failure (W: -47.6 ± 1.0%; M: -49.9 ± 1.3%). Rate of muscle fatigue was found to be similar between women and men (W: -3.6 ± 0.5 %·min(-1); M: -4.3 ± 0.6 %·min(-1)) and no gender difference was found in the recovery of muscle strength following task failure. In summary, no gender difference was found in the fatigability of the forearm muscles during intermittent submaximal handgrip contractions, independent of muscle strength. Key pointsThe aim of the present study was to determine if gender differences exist in forearm muscle fatigue during intermittent isometric handgrip contractions.Both unmatched and matched for strength gender comparisons found women and men to exhibit a similar exercise tolerance, rate of fatigue, and recov-ery of handgrip force following repeated forearm muscle contractions.These results indicate that maximal handgrip strength is not a key determinant of exercise toler-ance during intermittent isometric forearm exercise performed at a moderate relative contraction inten-sity.
authors.affiliation: Cardiopulmonary and Metabolism Research Laboratory, Department of Kinesiology, The University of Toledo, Toledo, Ohio USA.
authors.forename: Joaquin U
authors.initials: JU
authors.lastname: Gonzales
authors.forename: Barry W
authors.initials: BW
authors.lastname: Scheuermann
keywords: Muscle fatigue; gender differences; handgrip