PURPOSE American College of Sports Medicine (ACSM) metabolic equations are used to estimate energy expenditure (EE) of physical activity and prescribe aerobic exercise to meet EE requirements. Limited evidence supports their accuracy in sedentary adults with overweight or obesity during controlled exercise interventions. The purpose of this study was to compare EE estimated by the ACSM walking equation versus EE measured by indirect calorimetry during a 24-week aerobic exercise intervention, and identify potential modulators for their accuracy. METHODS Data from the exercising groups (8 or 20 kcal·kg body weight-1·week-1) of the E-MECHANIC study were utilized in this ancillary analysis (N = 103). Every 2 weeks for the initial 8 weeks and monthly thereafter, EE was measured via indirect calorimetry during absolute (2 mph, 0% grade) and relative (65-85% VO2peak) workload exercise. Resting metabolic rate, VO2peak, and body composition were assessed at baseline and follow-up. An EE offset factor (EOF) was calculated to express measured EE as a percentage of the estimated EE at each workload (EOF < 100% represents an overestimation of ACSM estimated EE). RESULTS The accuracy of the equation decreased with increasing exercise workload (0.44%, 9.2%, and 20.3% overestimation at absolute, relative, and maximal workloads, respectively, at baseline) and overestimation of EE was greater after the exercise intervention. Furthermore, race, sex, age, fat mass, and VO2peak were identified as modulators for equation accuracy. Greater overestimation of EE was observed in Black compared to white females, particularly at lower exercise workloads. CONCLUSIONS These findings support future efforts to improve the accuracy of metabolic equations, especially in diverse populations. Researchers should account for exercise efficiency adaptations when using metabolic equations to prescribe exercise precisely.

中文翻译：

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超重或肥胖成人能量消耗准确性的调节剂：E-MECHANIC 二次分析。


目的 美国运动医学会 （ACSM） 代谢方程用于估计身体活动的能量消耗 （EE） 并规定有氧运动以满足 EE 要求。有限的证据支持它们在控制运动干预期间久坐不动的超重或肥胖成年人中的准确性。本研究的目的是比较在 24 周有氧运动干预期间通过 ACSM 步行方程估计的 EE 与通过间接量热法测量的 EE，并确定其准确性的潜在调节剂。方法 本辅助分析使用了来自 E-MECHANIC 研究的运动组 （8 或 20 kcal·kg 体重-1·周-1） 的数据 （N = 103）。在最初的 8 周和此后每月每 2 周一次，在绝对 （2 mph，0% 等级） 和相对 （65-85% VO2peak） 负荷运动期间通过间接量热法测量 EE。在基线和随访时评估静息代谢率、 VO2 峰值和身体成分。计算 EE 偏移因子 （EOF） 以表示测得的 EE 占每个工作负载估计 EE 的百分比（EOF < 100% 表示高估了 ACSM 估计的 EE）。结果 方程的准确性随着运动工作量的增加而降低 （基线时绝对、相对和最大负荷分别高估了 0.44% 、 9.2% 和 20.3%），运动干预后 EE 的高估更大。此外，种族、性别、年龄、脂肪量和 VO2peak 被确定为方程准确性的调节因子。与白人女性相比，黑人对 EE 的估计更高，尤其是在较低的运动负荷下。结论这些发现支持未来提高代谢方程准确性的努力，尤其是在不同的人群中。 研究人员在使用代谢方程精确规定运动时，应考虑运动效率的适应。