Faculty Collaboration Database

Stressor-induced increase in muscle fatigability of young men and women is predicted by strength but not voluntary activation. J Appl Physiol (1985) 2014 Apr 01;116(7):767-78

Date

02/15/2014

Pubmed ID

24526582

Pubmed Central ID

PMC3972745

DOI

10.1152/japplphysiol.01129.2013

Scopus ID

2-s2.0-84901218506 (requires institutional sign-in at Scopus site)   39 Citations

Abstract

This study investigated mechanisms for the stressor-induced changes in muscle fatigability in men and women. Participants performed an isometric-fatiguing contraction at 20% maximal voluntary contraction (MVC) until failure with the elbow flexor muscles. Study one (n = 55; 29 women) involved two experimental sessions: 1) a high-stressor session that required a difficult mental-math task before and during a fatiguing contraction and 2) a control session with no mental math. For some participants (n = 28; 14 women), cortical stimulation was used to examine mechanisms that contributed to muscle fatigability during the high-stressor and control sessions. Study two (n = 23; nine women) determined the influence of a low stressor, i.e., a simple mental-math task, on muscle fatigability. In study one, the time-to-task failure was less for the high-stressor session than control (P < 0.05) for women (19.4%) and men (9.5%): the sex difference response disappeared when covaried for initial strength (MVC). MVC force, voluntary activation, and peak-twitch amplitude decreased similarly for the control and high-stressor sessions (P < 0.05). In study two, the time-to-task failure of men or women was not influenced by the low stressor (P > 0.05). The greater fatigability, when exposed to a high stressor during a low-force task, was not exclusive to women but involved a strength-related mechanism in both weaker men and women that accelerated declines in voluntary activation and slowing of contractile properties.

Author List

Keller-Ross ML, Pereira HM, Pruse J, Yoon T, Schlinder-Delap B, Nielson KA, Hunter SK

Author

Kristy Nielson PhD Professor in the Psychology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Age Factors
Cognition
Evoked Potentials, Motor
Female
Humans
Isometric Contraction
Male
Motor Cortex
Muscle Fatigue
Muscle Strength
Muscle, Skeletal
Sex Factors
Stress, Psychological
Time Factors
Transcranial Magnetic Stimulation
Volition
Young Adult