ORIGINAL RESEARCH article
Front. Sports Act. Living
Sec. Elite Sports and Performance Enhancement
Profiling Measures of Muscle Strength and Power Throughout a 156-km Ultra-Trail Running Event
Provisionally accepted
Adrian Markov1
Ben J Edwards2
Arnaud GOUTORBE3Sonia GILLI3
Marcel Lemire4
AnhPhong David Nguyen5
Benoit MAUVIEUX3*- 1Université de Caen Normandie, Caen, France
- 2Liverpool John Moores University, Liverpool, United Kingdom
- 3Universite de Caen Normandie, Caen, France
- 4Universite de Strasbourg, Strasbourg, France
- 5Universite catholique de Louvain, Louvain-la-Neuve, Belgium
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Purpose: Ultra-endurance performance involves complex neuromuscular demands, yet continuous in-race assessment of strength and power development is lacking. This study examined the first-ever continuous profile of neuromuscular fatigue throughout an entire ultra-trail race to understand fatigue mechanisms and inform training and pacing strategies. Methods: Fifty-five participants (43 men, 12 women; 45.2 ± 13.6 years) completed six identical 26 km laps with 1000 m elevation gain and loss per lap. Maximum knee-extensor and handgrip strength, peak-power output, and jump-height were measured pre-race, after each lap, and 12 h post-race using standardized protocols and linear mixed models. Results: Knee-extensor strength decreased by ~41% from pre-race to finish (p < .001), with substantial recovery (Δ26–27%) at 12 h post-race. Handgrip strength showed minimal overall decline (Δ~2–5%), suggesting fatigue localized to the lower limbs. Peak-power and jump-height declined gradually (Δ6–7% from early laps; p < .001). Critically, no significant relationship existed between the magnitude of strength loss and final ranking (early and late finishers showed no differences in strength profiles). However, participants who withdrew at lap 5 displayed substantially lower baseline strength (Δ27%; p = .004) and progressive strength declines compared to finishers, suggesting baseline neuromuscular capacity may influence completion likelihood. Conclusion: Continuous in-race profiling reveals that ultra-trail running induces substantial and predominantly peripheral neuromuscular fatigue in the lower limbs, with limited systemic effects. While strength loss magnitude does not predict race placement among finishers, lower baseline strength may increase non-completion risk. These findings underscore the importance of targeted strength training and metabolite-clearance strategies (e.g., glycogen replenishment, hydration, recovery) in ultra-endurance preparation.
Keywords: Fatigue, Finisher, non-finisher, Trail-running, Ultra-Endurance
Received: 29 Oct 2025; Accepted: 08 Dec 2025.
Copyright: © 2025 Markov, Edwards, GOUTORBE, GILLI, Lemire, Nguyen and MAUVIEUX. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Benoit MAUVIEUX
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.