Influence of Sex on the Recovery Response Following Isometric Exercise Performed at Long Muscle Length

ABSTRACT: Rosaci, G, Nigro, F, Marcora, SM, and Bartolomei, S. Influence of Sex on the Recovery Response Following Isometric Exercise Performed at Long Muscle Length. J Strength Cond Res XX(X): 000-000, 2026-The aim of the study was to compare the recovery responses of the pectoralis major muscle in men and women after isometric exercise. Twelve men (age: 25.3 ± 4.1 years; height: 177.6 ± 7.4 cm; body mass: 81.6 ± 10.1; training experience: 6.7 ± 3.7) and 10 women (age: 24.5 ± 1.4 years; height: 166.4 ± 6.7 cm; body mass: 62.5 ± 7.4; training experience: 5.0 ± 2.7) performed a high-intensity (maximum effort) intermittent isometric exercise at long muscle length (LML) for the pectoralis major muscle. Peak force at LML and short muscle length, average power at bench throw power test, muscle architecture (muscle thickness and corrected echo intensity), and muscle soreness were assessed before, and 15 minutes, 24 and 48 hours postexercise. Rate of perceived exertion was also collected 15 minutes postexercise. Although men were significantly stronger that women, no sex differences were detected in changes of peak force at LML (p ≥ 0.184) and short muscle length (p ≥ 0.514), muscle architecture (p ≥ 0.552), soreness (p ≥ 0.09), and on rate of perceived exertion (p ≥ 0.452). However, a greater drop in average power at the bench throw power test was registered in men compared with women 15 minutes postexercise (p < 0.001, d = 2.36). Although similar patterns of muscle recovery were observed in men and women, a sex-related difference may exist in the acute effects of isometric exercise on power exertion. Men indeed may be more sensitive to acute fatigue and more prone to power reductions after isometric exercise.