Department of Kinesiology, Faculty of Medicine, PEPS, Université Laval, Quebec City, G1V 0A6, Canada.
Centre Nutrition, Santé et Société (NUTRISS), Institute of Nutrition and Functional Food (INAF), Quebec City, Canada.
Eur J Appl Physiol. 2024 Dec;124(12):3661-3670. doi: 10.1007/s00421-024-05528-w. Epub 2024 Jul 28.
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/ (vO-vOseated 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.
本研究旨在评估净机械效率（NME）与身体成分和血糖特征之间的关联，研究对象为魁北克家庭研究（QFS）中的中年参与者（38.3±14.3 岁）。分析对象为 605 名参与者（271 名男性和 334 名女性），他们在测力计上进行了亚最大强度运动测试，该测试由三个连续 6 分钟的递增强度工作量组成，在此期间评估了呼吸气体交换。NME[功率输出/（vO-运动前静息时的 vO）]的计算基于第一工作量的最后 3 分钟，目标功率输出为 30 W。在对年龄进行调整后，分别对男性和女性中的 NME 与因变量之间的相关性进行了计算。通过比较按 NME 性别特异性三分位数分类的受试者组，评估了 NME 与身体成分和葡萄糖-胰岛素变量之间的关联。在两性中均观察到 NME 与身体成分和血糖特征呈显著负相关。在进一步调整剧烈体力活动、心肺健康和平均运动呼吸交换比后，对三分位数进行比较显示，具有高 NME 的个体表现出更有利的肥胖和血糖特征。然而，在进一步调整体脂百分比后，大多数葡萄糖-胰岛素变量的差异变得无统计学意义。QFS 家族数据表明，NME 的遗传度约为 30%。综上所述，本研究结果表明，除了有氧适能和体力活动参与外，机械效率是一个与身体成分和血糖特征变化独立相关的额外活动相关变量。
