Fatigue and recovery from dynamic contractions in men and women differ for arm and leg muscles.

Introduction: Whether there is a gender difference in fatigue and recovery from maximal velocity fatiguing contractions and across muscles is not understood.
Methods: Sixteen men and 19 women performed 90 isotonic contractions at maximal voluntary shortening velocity (maximal velocity concentric contractions, MVCC) with the elbow flexor and knee extensor muscles (separate days) at a load equivalent to 20% maximal voluntary isometric contraction (MVIC).
Results: Power (from MVCCs) decreased similarly for men and women for both muscles (P > 0.05). Men and women had similar declines in MVIC of elbow flexors, but men had greater reductions in knee extensor MVIC force and MVIC electromyogram activity than women (P < 0.05). The decline in MVIC and power was greater, and force recovery was slower for the elbow flexors compared with knee extensors.
Conclusions: The gender difference in muscle fatigue often observed during isometric tasks was diminished during fast dynamic contractions for upper and lower limb muscles.
(Copyright © Published 2013 by Wiley Periodicals, Inc. This article is a US Government wmusork and, as such, is in the public domain in the United States of America.)