Sex differences for fatigue-induced changes in muscle blood flow, but not eccentric peak torque or neuromuscular responses

J Musculoskelet Neuronal Interact. 2018 Dec 1;18(4):427-437.

Abstract

Objectives: The purpose of this study was to examine the effects of exercise intensity and strength on sex-related differences in eccentric peak torque (PT), muscle blood flow, and neuromuscular responses following fatiguing, submaximal forearm flexion eccentric protocols.

Methods: Thirty-six subjects were stratified by sex and strength into 4 equal groups and randomly performed fatiguing eccentric, isokinetic (180°·s-1), forearm flexion protocols at 40% or 80% of eccentric PT. Eccentric PT, muscle blood flow, and neuromuscular responses were measured prior to (pretest), immediately (posttest), and 5-min after (5-min recovery) performing the fatiguing protocols.

Results: There was no sex-, intensity-, or strength-related difference in the magnitude of decrease in eccentric PT at posttest (80.0% of pretest) or the magnitude of recovery at 5-min (87.8% of pretest). Muscle blood flow increased similarly for men (139.8% of pretest) and women (178.7% of pretest) at posttest, but the magnitude of recovery was greater for the women (62.9%) than the men (41.4%). The neuromuscular responses were not affected by sex-, intensity-, or strength-related differences.

Conclusions: These findings indicated that there were few sex-related differences in eccentric PT, muscle blood flow, and neuromuscular responses as a result of the fatiguing eccentric protocols performed at a high or low intensity of exercise.

MeSH terms

  • Adult
  • Blood Flow Velocity / physiology*
  • Electromyography / methods
  • Female
  • Humans
  • Male
  • Middle Aged
  • Muscle Contraction / physiology*
  • Muscle Fatigue / physiology*
  • Muscle, Skeletal / blood supply*
  • Muscle, Skeletal / physiology*
  • Sex Characteristics*
  • Young Adult