Human Movement Biomechanics Research Group, Department of Movement Science, KU Leuven, Tervuursevest 101, Mailbox 1501, 3001, Louvain, Belgium.
Integrative Locomotion Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, USA.
Eur J Appl Physiol. 2022 Dec;122(12):2565-2574. doi: 10.1007/s00421-022-05032-z. Epub 2022 Sep 5.
With few cycling races on the calendar in 2020 due to COVID-19, Everesting became a popular challenge: you select one hill and cycle up and down it until you reach the accumulated elevation of Mt. Everest (8,848 m or 29,029ft). With an almost infinite number of different hills across the world, the question arises what the optimal hill for Everesting would be. Here, we address the biomechanics and energetics of up- and downhill cycling to determine the characteristics of this optimal hill.
During uphill cycling, the mechanical power output equals the power necessary to overcome air resistance, rolling resistance, and work against gravity, and for a fast Everesting time, one should maximize this latter term. To determine the optimal section length (i.e., number of repetitions), we applied the critical power concept and assumed that the U-turn associated with an additional repetition comes with a 6 s time penalty.
To use most mechanical power to overcoming gravity, slopes of at least 12% are most suitable, especially since gross efficiency seems only minimally diminished on steeper slopes. Next, we found 24 repetitions to be optimal, yet this number slightly depends on the assumptions made. Finally, we discuss other factors (fueling, altitude, fatigue) not incorporated in the model but also affecting Everesting performances.
For a fast Everesting time, our model suggests to select a hill climb which preferably starts at (or close to) sea level, with a slope of 12-20% and length of 2-3 km.
由于 2020 年 COVID-19 的影响,自行车比赛数量较少,因此 Everest 挑战赛成为一项流行的挑战:您选择一座山,然后在山上上下骑行,直到达到珠穆朗玛峰(8848 米或 29029 英尺)的累计海拔高度。由于世界各地有无数不同的山丘,因此出现了一个问题,即进行 Everest 挑战赛的最佳山丘是哪一座。在这里,我们研究了上下坡骑行的生物力学和能量学,以确定这座最佳山丘的特点。
在上坡骑行过程中,机械功率输出等于克服空气阻力、滚动阻力和克服重力所需的功率,如果要快速完成 Everest 挑战赛,就应该使后者最大化。为了确定最佳的爬坡段长度(即重复次数),我们应用了临界功率概念,并假设由于额外重复一次而进行的折返会带来 6 秒的时间惩罚。
为了最大限度地利用机械功率来克服重力,坡度至少应为 12%,尤其是因为在更陡峭的坡度上总效率似乎仅略有下降。其次,我们发现 24 次重复是最佳的,但这个数字在一定程度上取决于所做的假设。最后,我们讨论了模型中未包含但也会影响 Everest 挑战赛表现的其他因素(燃料、海拔、疲劳)。
为了快速完成 Everest 挑战赛,我们的模型建议选择一个起始点(或接近)海平面、坡度为 12-20%、长度为 2-3 公里的爬坡段。