title: Effect of sex on torque, recovery, EMG, and MMG responses to fatigue.
abstract: The purpose of the present investigation was to examine the effect of sex on maximal voluntary isometric contraction (MVIC) torque and the EMG and MMG responses as a result of fatiguing, intermittent, submaximal (65% of MVIC), isometric elbow flexion muscle contractions.
  
  
  
  Eighteen men and women performed MVIC trials before (pretest), after (posttest), and 5-min after (5-min recovery) performing 50 intermittent, submaximal isometric muscle contractions. Surface electromyographic (EMG) and mechanomyographic (MMG) signals were simultaneously recorded from the biceps brachii muscle.
  
  
  
  As a result of the fatiguing workbout torque decreased similarly from pretest to posttest for both the men (24.0%) and women (23.3%). After 5-min of recovery, torque had partially recovered for the men, while torque had returned to pretest levels for the women. For both sexes, from pretest to posttest EMG mean power frequency and MMG amplitude decreased, but returned to pretest levels after 5-min of recovery.
  
  
  
  In the present study, there were sex-related differences in muscle fatigue that were not associated with the EMG or MMG responses.
authors.affiliation: Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, United States.
authors.forename: E C
authors.initials: EC
authors.lastname: Hill
authors.forename: T J
authors.initials: TJ
authors.lastname: Housh
authors.forename: C M
authors.initials: CM
authors.lastname: Smith
authors.forename: K C
authors.initials: KC
authors.lastname: Cochrane
authors.forename: N D M
authors.initials: NDM
authors.lastname: Jenkins
authors.forename: J T
authors.initials: JT
authors.lastname: Cramer
authors.forename: R J
authors.initials: RJ
authors.lastname: Schmidt
authors.forename: G O
authors.initials: GO
authors.lastname: Johnson
mesh_terms: D004594:Electrophysiology; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D012727:Sex Characteristics; D019415:Torque; D055815:Young Adult