Stressor-induced increase in muscle fatigability of young men and women is predicted by strength but not voluntary activation

Details

• Personal Author:
  Hunter SK ; Keller-Ross ML ; Nielson KA ; Pereira HM ; Pruse J ; Schlinder-Delap B ; Yoon T
• Description:
  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. [Description provided by NIOSH]
• Subjects:
  Age Factors Aging Fatigue Men Mental Health Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety Sex Characteristics Women

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• Keywords:
  Age-factors Age-groups Author Keywords: Gender Humans Mental-processes Muscle-physiology Muscle-stress Muscle-tension Muscle Fatigue Muscles Musculoskeletal-system Physiological-effects Physiological-fatigue Physiological-function Physiology Sex-factors Sex Differences Transcranial Magnetic Stimulation Voluntary Activation

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• ISSN:
  8750-7587
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Illinois ; Minnesota ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  116
• Issue:
  7
• NIOSHTIC Number:
  nn:20045483
• Citation:
  J Appl Physiol 2014 Apr; 116(7):767-778
• Contact Point Address:
  M. L. Keller-Ross, Dept. of Cardiovascular Diseases, Mayo Clinic and Foundation, 200 First St., S.W., Rochester, MN 55901
• Email:
  keller.manda@mayo.edu
• Federal Fiscal Year:
  2014
• Performing Organization:
  University of Illinois at Chicago
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Journal of Applied Physiology
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3142ea5a3d8758c5eb49477874d0d888e61c8103c1ee38de13257819567cfb790de81532a7bf15cc716e81cb63143722beeb05f12bcbce1905084c1c03860f36
• Download URL:
  https://stacks.cdc.gov/view/cdc/200889/cdc_200889_DS1.pdf
• File Type:
  [PDF - 640.47 KB ]