Vernillo Gianluca, Savoldelli Aldo, Zignoli Andrea, Skafidas Spyros, Fornasiero Alessandro, La Torre Antonio, Bortolan Lorenzo, Pellegrini Barbara, Schena Federico
a Department of Biomedical Sciences for Health , Università degli Studi di Milano , Milan , Italy.
c CeRiSM, Research Center "Sport, Mountain and Health" , Università degli Studi di Verona , Rovereto , ( TN ), Italy.
J Sports Sci. 2015;33(19):1998-2005. doi: 10.1080/02640414.2015.1022870. Epub 2015 Mar 9.
This study aimed to determine whether the fatigue induced by a mountain ultramarathon (MUM) led to changes in energy cost and kinematic during level and graded running. Pre- and post-race, 14 ultratrail runners ran on a level, uphill (5%) and downhill (5%) treadmill at 10 km · h(-1). Kinematic data were acquired using a photocell system. Post-race, the downhill energy cost increased by 13.1% (P < 0.001). No change was noted in level and uphill running. Duty factor and stride frequency were increased, whereas swing time, cycle time and stride length were decreased in all conditions (P < 0.05). Contact time was increased and the rate of force generation was decreased only in the uphill and downhill conditions (P < 0.05). Positive correlations were observed between performance time and the pre- to post-changes in the energy cost of level (r = 0.52, P = 0.04) and uphill running (r = 0.50, P = 0.04). MUM-induced fatigue resulted in physiological and spatiotemporal changes, though the response to fatigue varied considerably between running conditions. These changes resulted in a significant increment only in the downhill energy cost. Incorporating downhill locomotion in the training programmes of ultratrailers may help to improve performance-related physiological and biomechanical parameters.
本研究旨在确定山地超级马拉松（MUM）引发的疲劳是否会导致在平路和坡度跑过程中的能量消耗及运动学变化。在赛前和赛后，14名超级越野跑者在平路、上坡（5%）和下坡（5%）的跑步机上以10 km·h⁻¹的速度跑步。使用光电管系统采集运动学数据。赛后，下坡时的能量消耗增加了13.1%（P < 0.001）。平路和上坡跑时未发现变化。在所有情况下， Duty factor和步频增加，而摆动时间、周期时间和步幅减小（P < 0.05）。仅在上坡和下坡情况下，着地时间增加且力产生速率降低（P < 0.05）。在平路（r = 0.52，P = 0.04）和上坡跑（r = 0.50，P = 0.04）的能量消耗赛前至赛后变化与比赛成绩时间之间观察到正相关。MUM诱发的疲劳导致了生理和时空变化，尽管不同跑步条件下对疲劳的反应差异很大。这些变化仅导致下坡能量消耗显著增加。将下坡运动纳入超级越野跑者的训练计划可能有助于改善与成绩相关的生理和生物力学参数。
