Institute of Health and Biomedical Innovation and School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Kelvin Grove, Queensland, AUSTRALIA.
Med Sci Sports Exerc. 2015 Feb;47(2):307-14. doi: 10.1249/MSS.0000000000000421.
This study explores recent claims that humans exhibit minimum cost of transport (CoTmin) for running, which occurs at intermediate speed, and assesses individual physiological, gait, and training characteristics.
Twelve healthy participants with varying levels of fitness and running experience ran on a treadmill at six self-selected speeds in a discontinuous protocol over three sessions. Running speed (km·h), VO2 (mL·kg·km), CoT (kcal·km), HR (bpm), and cadence (steps per minute) were continuously measured. VO2max was measured on the fourth testing session. The occurrence of CoTmin was investigated, and its presence or absence was examined with respect to fitness, gait, and training characteristics.
Five participants showed clear CoTmin at intermediate speed and a statistically significant (P < 0.05) quadratic CoT-speed function, whereas the other participants did not show such evidence. Participants were then categorized and compared with respect to the strength of evidence for CoTmin (ClearCoTmin and NoCoTmin). The ClearCoTmin group displayed a significantly higher correlation between speed and cadence, more endurance training and exercise sessions per week, and a marginally nonsignificant but higher aerobic capacity than the NoCoTmin group. Some runners still showed CoTmin at intermediate speed even after subtraction of resting energy expenditure.
The findings confirm the existence of optimal speed for human running in some but not all participants. Those exhibiting COTmin undertook higher volume of running, ran with a cadence that was more consistently modulated with speed, and tended to be aerobically fitter. The ability to minimize energetic CoT seems not to be a ubiquitous feature of human running but may emerge in some individuals with extensive running experience.
本研究探讨了最近有关人类在跑步时表现出最小能量成本（CoTmin）的说法，即在中等速度下出现，并评估了个体生理、步态和训练特征。
12 名健康参与者具有不同的健身水平和跑步经验，在三个会话中的三个会话中以不连续的方案在跑步机上以六个自选速度跑步。连续测量跑步速度（km·h）、VO2（mL·kg·km）、CoT（kcal·km）、HR（bpm）和步频（每分钟步数）。在第四次测试会议上测量 VO2max。研究了 CoTmin 的发生情况，并根据健身、步态和训练特征检查了其存在与否。
5 名参与者在中等速度下表现出明显的 CoTmin 和统计学上显著的（P <0.05）二次 CoT-速度函数，而其他参与者则没有表现出这种证据。然后根据 CoTmin 的证据强度（ClearCoTmin 和 NoCoTmin）对参与者进行分类和比较。ClearCoTmin 组显示出速度与步频之间的相关性明显更高，耐力训练和每周运动次数更多，有氧能力略高于 NoCoTmin 组，但无统计学意义。即使减去静息能量消耗，一些跑步者在中等速度下仍显示出 CoTmin。
这些发现证实了在某些但不是所有参与者中存在人类跑步的最佳速度。那些表现出 COTmin 的人进行了更高量的跑步，以更一致的步频调节速度，并且往往更适合有氧运动。最小化能量 CoT 的能力似乎不是人类跑步的普遍特征，但可能在具有广泛跑步经验的某些个体中出现。
