School of Sport and Exercise Sciences, University of Kent, Kent, England, UK.
Med Sci Sports Exerc. 2013 May;45(5):920-6. doi: 10.1249/MSS.0b013e31827d1bdb.
The purpose of this study was to determine the effect of gradient on cycling gross efficiency and pedaling technique.
Eighteen trained cyclists were tested for efficiency, index of pedal force effectiveness (IFE), distribution of power production during the pedal revolution (dead center size [DC]), and timing and level of muscle activity of eight leg muscles. Cycling was performed on a treadmill at gradients of 0% (level), 4%, and 8%, each at three different cadences (60, 75, and 90 rev·min).
Efficiency was significantly decreased at a gradient of 8% compared with both 0% and 4% (P < 0.05). The relationship between cadence and efficiency was not changed by gradient (P > 0.05). At a gradient of 8%, there was a larger IFE between 45° and 225° and larger DC, compared with 0% and 4% (P < 0.05). The onset of muscle activity for vastus lateralis, vastus medialis, gastrocnemius lateralis, and gastrocnemius medialis occurred earlier with increasing gradient (all P < 0.05), whereas none of the muscles showed a change in offset (P > 0.05). Uphill cycling increased the overall muscle activity level (P < 0.05), mainly induced by increased calf muscle activity.
These results suggest that uphill cycling decreases cycling gross efficiency and is associated with changes in pedaling technique.
本研究旨在确定坡度对循环总效率和踏蹬技术的影响。
对 18 名训练有素的自行车运动员进行效率、蹬力效率指数（IFE）、蹬踏周期内动力产生分布（死点大小[DC]）、8 块腿部肌肉的肌肉活动时间和水平的测试。在坡度为 0%（水平）、4%和 8%的跑步机上，以 3 种不同的踏频（60、75 和 90 rev·min）进行测试。
与 0%和 4%相比，8%的坡度时效率显著降低（P<0.05）。坡度对效率和踏频的关系没有影响（P>0.05）。在 8%的坡度下，45°到 225°之间的 IFE 和 DC 比 0%和 4%时更大（P<0.05）。随着坡度的增加，股外侧肌、股直肌、腓肠肌外侧和腓肠肌内侧的肌肉活动起始时间更早（均 P<0.05），但没有任何肌肉的终止时间发生变化（P>0.05）。上坡骑行增加了整体肌肉活动水平（P<0.05），主要是由小腿肌肉活动增加引起的。
这些结果表明，上坡骑行降低了循环总效率，并与踏蹬技术的变化有关。
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