Purpose: To study the consequences of a fatiguing ultratrail run of 6 hours on self-optimizing capability during uphill and downhill (DR) running. Methods: The authors collected temporal stride kinematics and metabolic data in 8 (experimental group) male runners before and after the ultratrail run and in 6 (control group) male ultramarathon runners who did not run but stayed awake and performed normal, daily physical activities avoiding strenuous exercises over the 6-hour period. For each subject, preferred and optimal stride frequencies were measured, where stride frequency was systematically varied above and below the preferred one (±4% and ±8%) while running 3 conditions on level, 5% uphill, or 5% DR in a randomized order. Results: Preferred and optimal stride frequencies across grade, group, and time showed no significant differences (P ≥ .184). Metabolic cost and the energetically optimum metabolic cost showed a grade × group × time interaction (P ≥ .011), with an ∼11% increase in the 2 variables only during the DR bouts (P ≥ .037). Conclusions: Despite maintaining similar dynamics of stride frequency adjustments during the DR bout, the experimental group was not able to optimize its gait. This suggests that the DR section of ultratrail runs can introduce a perturbing factor in the runners’ optimization process, highlighting the need for incorporating DR bouts in the training programs of ultratrail runners to minimize the deleterious effects of DR on the energetically optimal gait.
Vernillo is with the Dept of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy. Mater and Mourot are with the EA3920 Prognostic Factors and Regulatory Factors of Cardiac and Vascular Pathologies, Exercise Performance Health Innovation (EPHI) Platform, University Bourgogne Franche-Comté, Besançon, France. Doucende is with the Laboratoire Européen Performance Santé Altitude (LEPSA), Université de Perpignan Via Domitia, Font Romeu, France. Cassirame is with the Laboratoire Culture, Sport, Santé et Société, Exercise and Performance Health Innovation (EPHI) platform, University Bourgogne Franche-Comté, Besançon, France. Mourot is with Tomsk Polytechnic University, Tomsk, Russia.
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VernilloG, SavoldelliA, SkafidasS, et al. An extreme mountain ultra-marathon decreases the cost of uphill walking and running. Front Physiol. 2016;7:530. PubMed ID: 27877137 doi:10.3389/fphys.2016.005302787713710.3389/fphys.2016.00530)| false
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VernilloG, SavoldelliA, ZignoliA, et al. Energy cost and kinematics of level, uphill and downhill running: fatigue-induced changes after a mountain ultramarathon. J Sports Sci. 2015;33:1998–2005. PubMed ID: 25751128 doi:10.1080/02640414.2015.10228702575112810.1080/02640414.2015.1022870)| false