Document Type
Article
Publication Date
10-2025
Publisher
Wiley
Source Publication
Physiological Reports
Source ISSN
2051-817X
Original Item ID
DOI: 10.14814/phy2.70581
Abstract
The mechanisms for the age-related increase in fatigability of the elbow flexor muscles during dynamic contractions are unknown. The purpose of this study was to determine the contribution of supraspinal and contractile mechanisms for the age-related increase in fatigability of the elbow flexor muscles. Twenty-eight young (23.2 ± 2.6 years; 14 females) and 32 older adults (72.6 ± 5.6 years; 15 females) performed 80 maximal velocity contractions at 20% of maximal isometric strength. Voluntary activation and muscle contractile properties were assessed before and immediately following the fatiguing exercise using transcranial magnetic stimulation (TMS) and electrical stimulation. Fatigability (% reduction in power) was greater in older (49.2%) than in young adults (37.6%; p = 0.01) with no differences between males and females (p = 0.36). Reductions in voluntary activation following exercise did not differ between young and older adults (p = 0.96). Reductions in peak rates of torque relaxation induced by TMS were greater in older (44.4%) than in young adults (22.8%; p < 0.001) and were associated with fatigability (r = 0.51, p < 0.001). These data suggest that the age-related increase in fatigability of the elbow flexors is due primarily to mechanisms that impair muscle contractile function.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Arney, Blaine E.; Kuplic, Andrew; Adam, Mitchell D.; Sundberg, Christopher W.; and Hunter, Sandra, "Mechanisms for the Age-Related Increase in Fatigability of the Elbow Flexor Muscles in Healthy Adults" (2025). Exercise Science Faculty Research and Publications. 254.
https://epublications.marquette.edu/exsci_fac/254
ADA Accessible Version
Comments
Published version. Physiological Reports, Vol. 13, No. 19 (October 2025): e70581. DOI. © 2025 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society. Used with permission.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.