Open AccessExternal mechanical work done during the acceleration stage of maximal sprint running and its association with running performance
Author(s) -
Akifumi Matsuo,
Mirai Mizutani,
Ryu Nagahara,
T. Fukunaga,
Hiroaki Kanehisa
Publication year - 2019
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.189258
Subject(s) - sprint , acceleration , work (physics) , mathematics , work output , zoology , physics , simulation , mechanics , control theory (sociology) , computer science , physical therapy , medicine , biology , thermodynamics , classical mechanics , control (management) , artificial intelligence
How external mechanical work done during maximal acceleration sprint running changes with increasing running velocity and is associated with running performance remains unknown. This study aimed to elucidate them. In twelve young males, work done at each step over 50 m from the start was calculated from mechanical energy changes in horizontal anterior-posterior and vertical directions and was divided into that in each of braking (negWkapand negWv, respectively) and propulsive (posWkap and posWv, respectively) phases. The maximal running velocity (Vmax) appeared at 35.87±7.76 m and the time required to run 50 m (T50m) was 7.11±0.54 s. At 80% Vmax or higher, posWkap largely decreased and negWkap abruptly increased. The change in the difference between posWkap and |negWkap| (ΔWkap) at every step was relatively small at 70% Vmax or lower. Total work done over 50 m was 82.4±7.5 J/kg for posWkap, 36.2±4.4 J/kg for |negWkap|, 14.3±1.9 J/kg for posWv, and 10.4±1.2 J/kg for |negWv|. The total ΔWkap over 50 m was more strongly correlated with T50m (r=−0.946, P<0.0001) than the corresponding associations for the other work variables. These results indicate that in maximal sprint running over 50 m, work done during the propulsive phase in the horizontal anterior-posterior direction accounts for the majority of the total external work done during the acceleration stage, and maximizing it while suppressing work done during the braking phase is essential to achieve a high running performance.