Document Type
Article
Language
eng
Format of Original
12 p.
Publication Date
1-11-2017
Publisher
American Physiological Society
Source Publication
Journal of Applied Physiology
Source ISSN
0021-8987
Abstract
The durations that muscular force and power outputs can be sustained until failure fall predictably on an exponential decline between an individual’s 3-s burst maximum to the maximum performance they can sustain aerobically. The exponential time constants describing these rates of performance loss are similar across individuals, suggesting that a common metabolically based mechanism governs muscle fatigue; however, these conclusions come from studies mainly on men. To test whether the same physiological understanding can be applied to women, we compared the performance-duration relationships and neuromuscular activity between seven men [23.3 ± 1.9 (SD) yr] and seven women (21.7 ± 1.8 yr) from multiple exhaustive bouts of cycle ergometry. Each subject performed trials to obtain the peak 3-s power output (Pmax), the mechanical power at the aerobic maximum (Paer), and 11–14 constant-load bouts eliciting failure between 3 and 300 s. Collectively, men and women performed 180 exhaustive bouts spanning an ~6-fold range of power outputs (118–1116 W) and an ~35-fold range of trial durations (8–283 s). Men generated 66% greater Pmax (956 ± 109 W vs. 632 ± 74 W) and 68% greater Paer (310 ± 47 W vs. 212 ± 15 W) than women. However, the metabolically based time constants describing the time course of performance loss were similar between men (0.020 ± 0.003/s) and women (0.021 ± 0.003/s). Additionally, the fatigue-induced increases in neuromuscular activity did not differ between the sexes when compared relative to the pedal forces at Paer. These data suggest that muscle fatigue during short-duration dynamic exercise has a common metabolically based mechanism determined by the extent that ATP is resynthesized by anaerobic metabolism.
Recommended Citation
Sundberg, Christopher W.; Hunter, Sandra K.; and Bundle, Matthew W., "Rates of Performance Loss and Neuromuscular Activity in Men and Women During Cycling: Evidence for A Common Metabolic Basis of Muscle Fatigue" (2017). Exercise Science Faculty Research and Publications. 103.
https://epublications.marquette.edu/exsci_fac/103
Comments
Accepted version. Journal of Applied Physiology, Vol. 122, No. 1 (January 11, 2017): 130-141. DOI. © 2017 American Physiological Society. Used with permission.