Samozino Pierre, Horvais Nicolas, Hintzy Frédérique
Laboratoire de Modélisation des Activités Sportives, Université de Savoie-CISM, 73-376, Bourget du lac, France.
Eur J Appl Physiol. 2006 May;97(1):133-9. doi: 10.1007/s00421-006-0132-x. Epub 2006 Feb 1.
The purpose of this study was to investigate the interactions between cadence and power output effects on cycling efficiency. Fourteen healthy subjects performed four constant power output-tests (40, 80, 120 and 160 W) in which the cadence varied in five bouts from 40 to 120 rpm. Gross efficiency (GE) was determined over the last ten respiratory cycles of each bout and was calculated as the ratio of mechanical energy to energy expenditure. Results showed that (1) GE-cadence relationships reached a maximum at each power output corresponding to the cadence maximising efficiency (CAeff) and (2) GE increased with power output whatever the cadence until a maximal theoretical value. Moreover, interactions were found between these two factors: the cadence effect decreased linearly with power output and the power output effect increased exponentially with cadence. Consequently, cycling efficiency decreased more when cadence differed from CAeff at low than at high power output, and increased more with power output at high cadence than at low cadence. These interactions between cadence and power output effects on GE were mainly due to cadence and power output effects on the energy expenditure shares not contributing to power production.
本研究的目的是调查踏频与功率输出对骑行效率的影响之间的相互作用。14名健康受试者进行了四项恒定功率输出测试（40、80、120和160瓦），其中踏频在五个回合中从40至120转/分钟变化。在每个回合的最后十个呼吸周期测定总效率（GE），并将其计算为机械能与能量消耗的比率。结果表明：（1）GE-踏频关系在对应于使效率最大化的踏频（CAeff）的每个功率输出下达到最大值；（2）无论踏频如何，GE均随功率输出增加，直至达到最大理论值。此外，发现这两个因素之间存在相互作用：踏频效应随功率输出呈线性下降，功率输出效应随踏频呈指数增加。因此，与高功率输出相比，低功率输出时踏频与CAeff不同时骑行效率下降更多，且高踏频时功率输出增加导致的骑行效率增加比低踏频时更多。踏频和功率输出对GE的这些相互作用主要归因于踏频和功率输出对不用于产生功率的能量消耗份额的影响。
