Ardigò L P, Saibene F, Minetti A E
Centre for Biophysical and Clinical Research into Human Movement (CRM), Manchester Metropolitan University, Hassall Road, Alsager, Manchester, ST7 2HL, UK.
Eur J Appl Physiol. 2003 Oct;90(3-4):365-71. doi: 10.1007/s00421-003-0882-7. Epub 2003 Jul 25.
On level ground, cycling is more economical than running, which in turn is more economical than walking in the high speed range. This paper investigates whether this ranking still holds when moving on a gradient, where the three modes are expected to be mainly facing the same burden, i.e. to counter gravity. By using data from the literature we have built a theoretical framework to predict the optimal mode as a function of the gradient. Cycling was found to be the mode of choice only below 10-15% gradient, while above it walking was the least expensive locomotion type. Seven amateur bikers were then asked to walk, run and ride on a treadmill at different gradients. The speed was set so as to maintain almost constant the metabolic demand across the different gradients. The results indicate that the "critical slope", i.e. the one above which walking is less expensive than cycling (and running), is about 13-15%. One subject was loaded during bipedal gaits with a bicycle-equivalent mass, to simulate to cross-country cycling situation. The critical slope was close to 20%, due to the higher metabolic cost of loaded walking and running. Part of the findings can be explained by the mechanically different paradigms of the three locomotion types.
在平地上，骑自行车比跑步更经济，而在高速范围内跑步又比步行更经济。本文研究当在斜坡上移动时这种排序是否仍然成立，在斜坡上这三种运动方式预计主要面临相同的负担，即克服重力。通过使用文献中的数据，我们构建了一个理论框架来预测作为坡度函数的最佳运动方式。研究发现，只有在坡度低于10% - 15%时，骑自行车才是首选方式，而在该坡度以上，步行是成本最低的运动类型。然后，七名业余自行车骑行者被要求在不同坡度的跑步机上行走、跑步和骑行。速度被设定为在不同坡度下保持代谢需求几乎恒定。结果表明，“临界坡度”，即步行比骑自行车（和跑步）成本更低的坡度，约为13% - 15%。在双足步态期间，一名受试者背负与自行车相当的重量，以模拟越野骑行情况。由于负重行走和跑步的代谢成本较高，临界坡度接近20%。部分研究结果可以通过这三种运动类型在机械原理上的不同范式来解释。
