UBC Theses and Dissertations
Alterations in countermovement jump performance following completion of a mountainous ultramarathon Schmitt, Ethan
Abstract
BACKGROUND: Ultramarathons lie on the extreme end of endurance sport duration. With ultramarathon participation increasing in recent years, there is a need for more research to understand factors that influence ultramarathon performance, and the potential effects of completing an ultramarathon on muscular fatigue. This study investigated countermovement jump mechanics in ultramarathon runners and identified potential changes following a race. METHODS: Twenty-one runners (6 female, 15 male) were recruited from an ultramarathon trail race. Runners were examined before and after ultra-endurance races of 64 km, 80 km, 100 km, and 192 km. Height, weight, percentage body fat were collected, and the participants performed five jumps on a dual force plate system (Hawkin Dynamics, USA) to assess jump height, as well as related force-time variables in the braking and propulsive phases of the jump. Paired samples T-tests were conducted to assess changes from pre- to post. Pearson product correlations were calculated to determine the association between indices of vertical ground reaction forces and race performance RESULTS: Significant decreases were observed in jump height (-33.6 ± 17%, p < 0.001), average relative net braking impulse (-33.1 ± 19 % change, p < 0.001), braking rate of force development (-60.1 ± 25%, p < 0.001), and propulsive net impulse (-19.3 ± 11%, p < 0.001). Significant increases were observed in braking phase time (s) (52.7 ± 55%, p < 0.001), and propulsive phase time (s) (8.85 ± 16%, p = 0.012). Peak propulsive force was not significantly different between pre- and post-race (-1.39 ± 9.8%, p = 0.474) No countermovement jump variables displayed significant correlations to relative finishing time. However, both body weight (r = 0.49, p = 0.025), and BMI (r = 0.52, p = 0.015), demonstrated significant associations with race performance. CONCLUSION: Ultramarathons elicit altered jump timing, limiting the ability to use elastic energy, but does not affect maximal concentric force generated. This research may translate to improving strength training or running programs for ultrarunners.
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Attribution-NonCommercial-NoDerivatives 4.0 International