School of Human Kinetics, Laurentian University, Sudbury, ON, Canada.
Int J Sports Physiol Perform. 2012 Dec;7(4):382-9. doi: 10.1123/ijspp.7.4.382. Epub 2012 Jul 31.
Mechanical efficiency (ME) describes the ratio between mechanical (PMECH) and metabolic (PMET) power. The purpose of the study was to include an estimation of anaerobic energy expenditure (AnE) into the quantification of PMET using the accumulated oxygen deficit (AOD) and to examine its effect on the value of ME in treadmill running at submaximal, maximal, and supramaximal running speeds.
Participants (N = 11) underwent a graded maximal exercise test to determine velocity at peak oxygen uptake (vVO2peak). On 4 separate occasions, subjects ran for 6 min at speeds corresponding to 50%, 70%, 90%, and 110% of vVO2peak. During each testing session, PMET was measured from pulmonary oxygen uptake (VO2p) using open-circuit spirometry and was quantified in 2 ways: from VO2p and an estimate of AnE (from the AOD method) and from VO2p only. PMECH was determined from kinematic analyses.
ME at 50%, 70%, 90%, and 110% of vVO2peak was 59.9% ± 11.9%, 55.4% ± 12.2%, 51.5% ± 6.8%, and 52.9% ± 7.5%, respectively, when AnE was included in the calculation of PMET. The exclusion of AnE yielded significantly greater values of ME at all speeds: 62.9% ± 11.4%, 62.4% ± 12.6%, 55.1% ± 6.2%, and 64.2% ± 8.4%; P = .001 (for 50%, 70%, 90%, and 110% of vVO2peak, respectively).
The data suggest that an estimate of AnE should be considered in the computation of PMET when determining ME of treadmill running, as its exclusion leads to overestimations of ME values.
机械效率（ME）描述了机械（PMECH）和代谢（PMET）功率之间的比率。本研究的目的是在使用累积氧亏（AOD）量化 PMET 时纳入对无氧能量消耗（AnE）的估计，并检查其对在跑步机上以亚最大、最大和超最大速度跑步时 ME 值的影响。
参与者（N=11）进行了分级最大运动测试，以确定峰值摄氧量（vVO2peak）时的速度。在 4 个不同的场合，受试者以 50%、70%、90%和 110%vVO2peak 的速度跑步 6 分钟。在每次测试中，使用开路肺活量计从肺摄取的氧气（VO2p）测量 PMET，并通过两种方式进行量化：从 VO2p 和 AnE 的估计值（从 AOD 方法）和仅从 VO2p。PMECH 是从运动学分析中确定的。
当在计算 PMET 时包含 AnE 时，在 vVO2peak 的 50%、70%、90%和 110%时，ME 分别为 59.9%±11.9%、55.4%±12.2%、51.5%±6.8%和 52.9%±7.5%。在所有速度下，排除 AnE 会导致 ME 值显著增加：62.9%±11.4%、62.4%±12.6%、55.1%±6.2%和 64.2%±8.4%；P=0.001（分别对应于 vVO2peak 的 50%、70%、90%和 110%）。
数据表明，在确定跑步机跑步的 ME 时，应考虑对 AnE 的估计，因为排除它会导致 ME 值的高估。
