Abstract：
The aim of this study was to assess the association between net mechanical efficiency (NME) and body composition and glycemic profile, in middle-aged (38.3 ± 14.3 years) participants from the Quebec Family Study (QFS). Analyses were completed on a sample of 605 participants (271 males and 334 females) who performed a submaximal exercise test on an ergometer consisting of three consecutive 6-min workloads at increasing intensity during which respiratory gas exchange was assessed. The calculation of NME [power output/ (vO2-vO2seated before exercise)] was based on the values of the last 3 min of the first workload at a targeted power output of 30 W. Correlations between NME and dependent variables were computed separately in males and females. Associations between NME and body composition and glucose-insulin variables were assessed by comparing groups of subjects categorized in sex-specific tertiles of NME after adjustments for age. Significant negative correlations were observed between NME and body composition and glycemic profile in both sexes. Comparison across tertiles showed that individuals with high NME displayed more favorable adiposity and glycemic profiles. These differences remained significant after further adjustments for participation in vigorous physical activity, cardiorespiratory fitness, and mean exercise respiratory exchange ratio whereas most differences in glucose-insulin variables became non-significant after further adjustment for percent body fat. QFS familial data indicate that the heritability of NME reaches about 30%. In conclusion, the results of this study show that beyond aerobic fitness and physical activity-participation, mechanical efficiency is an additional activity-related variable that is independently associated with variations in body composition and glycemic profile.
摘要：
这项研究的目的是评估净机械效率（NME）与身体成分和血糖状况之间的关联。魁北克家庭研究（QFS）的中年（38.3±14.3岁）参与者。对605名参与者（271名男性和334名女性）的样本进行了分析，这些参与者在测力计上进行了次最大运动测试，该测力计由三个连续6分钟的工作量组成，在此期间评估了呼吸气体交换。NME[功率输出/（运动前的vO2-vO2）]的计算是基于在30W的目标功率输出下第一个工作负荷的最后3分钟的值。男性和女性分别计算了NME与因变量之间的相关性。NME与身体成分和葡萄糖-胰岛素变量之间的关联是通过比较在调整年龄后按NME的性别特异性三元组分类的受试者组来评估的。在两种性别中，NME与身体组成和血糖状况之间均观察到显着的负相关。跨三分位数的比较表明，具有高NME的个体显示出更有利的肥胖和血糖分布。在进一步调整参加剧烈的体力活动后，这些差异仍然很大，心肺健康，和平均运动呼吸交换率，而在进一步调整体脂百分比后，葡萄糖-胰岛素变量的大多数差异变得无显着。QFS家族数据表明，NME的遗传力达到约30％。总之,这项研究的结果表明，除了有氧健身和体育活动参与，机械效率是一个额外的活动相关变量，它与身体成分和血糖分布的变化独立相关。
