Abstract
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) attempted six identical 26 km laps with 1,000 m elevation gain and loss per lap, 14 did not complete the course. 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 26%–27%) at 12 h post-race. Handgrip strength showed minimal overall decline (∼2%–5%), suggesting fatigue localized to the lower limbs. Peak-power and jump-height declined gradually (6%–7% from early laps; 27%; = .004) and progressive strength declines compared to finishers, suggesting baseline neuromuscular capacity may influence completion likelihood.
Description
The study profiles muscle strength and power in ultra-trail runners during a 156 km race.