Bouillod Anthony, Grappe Frederic
a EA4660, C3S Health - Sport Department , Sports University , Besancon , France.
b French Cycling Federation , Saint Quentin en Yvelines , France.
J Sports Sci. 2018 May;36(10):1173-1178. doi: 10.1080/02640414.2017.1363902. Epub 2017 Aug 4.
Cyclists regularly change from a seated to a standing position when the gradient increases during uphill cycling. The aim of this study was to analyse the physiological and biomechanical responses between seated and standing positions during distance-based uphill time trials in elite cyclists. Thirteen elite cyclists completed two testing sessions that included an incremental-specific cycling test on a cycle ergometer to determine VO and three distance-based uphill time trials in the field to determine physiological and biomechanical variables. The change from seated to standing position did not influence physiological variables. However, power output was increased by 12.6% in standing position when compared with seated position, whereas speed was similar between the two positions. That involved a significant increase in mechanical cost and tangential force (F) on the pedal (+19% and +22.4%, respectively) and a decrease (-8%) in the pedalling cadence. Additionally, cyclists spent 22.4% of their time in the standing position during the climbing time trials. Our findings showed that cyclists alternated between seated and standing positions in order to maintain a constant speed by adjusting the balance between pedalling cadence and F.
在上坡骑行过程中，当坡度增加时，自行车骑行者会经常从坐姿转换为站姿。本研究的目的是分析精英自行车运动员在基于距离的上坡计时赛中，坐姿和站姿之间的生理和生物力学反应。13名精英自行车运动员完成了两个测试环节，包括在自行车测力计上进行递增特异性骑行测试以确定最大摄氧量（VO₂max），以及在野外进行三次基于距离的上坡计时赛以确定生理和生物力学变量。从坐姿转换为站姿并未影响生理变量。然而，与坐姿相比，站姿时的功率输出增加了12.6%，而两个姿势下的速度相似。这涉及到机械成本和踏板切向力（F）显著增加（分别增加19%和22.4%）以及踏频降低（-8%）。此外，在爬坡计时赛中，自行车骑行者有22.4%的时间处于站姿。我们的研究结果表明，自行车骑行者在坐姿和站姿之间交替，以便通过调整踏频和切向力之间的平衡来保持恒定速度。
