Effects of obesity and sex on the energetic cost and preferred speed of walking
Effects of obesity and sex on the energetic cost and preferred speed of walking
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DOI：
10.1152/japplphysiol.00767.2005
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发表时间：
2006-02-01
影响因子：
3.3
通讯作者：
Kram, R
中科院分区：
文献类型：
--
作者：
Browning, RC;Baker, EA;Kram, R
步行的代谢能量消耗在很大程度上取决于体重，但尚不清楚身体成分和体重分布如何影响这种消耗。我们测试了这样一个假设，即与肥胖男性和正常体重的女性和男性相比，肥胖女性的步行费用最高。此外，我们假设，对于所有组，首选步行速度将对应于最小化单位距离总能量成本的速度。我们测量了39名（19名II级肥胖，20名正常体重）女性和男性的身体成分，最大耗氧量和首选步行速度。我们还测量了受试者以六种速度（0.50-1.75 m/s）在水平跑步机上行走时的耗氧量和二氧化碳产生量。肥胖和性别都影响步行的净代谢率（W/kg）。肥胖受试者的净代谢率仅比正常体重受试者高出10%（每公斤），女性的净代谢率比男性高出10%。与其他组相比，肥胖女性在较快的步行速度下净代谢率的增加最大。各组之间的首选步行速度没有差异（1.42 m/s），并且接近使单位距离总能量成本最小化的速度。令人惊讶的是，质量分布（大腿质量/体重）与净代谢率无关，但身体成分（%脂肪）与净代谢率相关（r（2）= 0.43）。需要对步行进行详细的生物力学研究，以调查肥胖者在步行过程中是否采用了新的节能机制。
The metabolic energy cost of walking is determined, to a large degree, by body mass, but it is not clear how body composition and mass distribution influence this cost. We tested the hypothesis that walking would be most expensive for obese women compared with obese men and normal-weight women and men. Furthermore, we hypothesized that for all groups, preferred walking speed would correspond to the speed that minimized the gross energy cost per distance. We measured body composition, maximal oxygen consumption, and preferred walking speed of 39 (19 class II obese, 20 normal weight) women and men. We also measured oxygen consumption and carbon dioxide production while the subjects walked on a level treadmill at six speeds (0.50-1.75 m/s). Both obesity and sex affected the net metabolic rate (W/kg) of walking. Net metabolic rates of obese subjects were only similar to 10% greater (per kg) than for normal-weight subjects, and net metabolic rates for women were similar to 10% greater than for men. The increase in net metabolic rate at faster walking speeds was greatest in obese women compared with the other groups. Preferred walking speed was not different across groups (1.42 m/s) and was near the speed that minimized gross energy cost per distance. Surprisingly, mass distribution (thigh mass/body mass) was not related to net metabolic rate, but body composition (% fat) was (r(2) = 0.43). Detailed biomechanical studies of walking are needed to investigate whether obese individuals adopt novel energy saving mechanisms during walking.