VOmax is associated with measures of energy expenditure in sedentary condition but does not predict weight change.

BACKGROUND/OBJECTIVES: Energy expenditure measured under sedentary conditions predicts weight change but evidence that directly measured VOmax is associated with weight change is lacking. The aim of this study was to determine the associations of VOmax with measures of predominantly sedentary 24-h thermogenesis, and subsequent weight change.

SUBJECTS/METHODS: Three hundred fifty-seven individuals (162 females; 27 Blacks, 72 Caucasians, and 258 American Indians) had measures of body composition, resting metabolic rate (RMR), and intermittent treadmill run test for assessment of VOmax. On a separate day, 24-h energy expenditure (EE), diet-induced thermogenesis (DIT) expressed as "awake and fed" thermogenesis (AFT), sleeping metabolic rate (SMR), and spontaneous physical activity (SPA) were measured in a whole-room indirect calorimeter. Follow-up weight for 217 individuals was available (median follow-up time, 9.5 y; mean weight change, 12.4 ± 14.9 kg).

RESULTS

After adjustment for fat free mass, fat mass, age, sex, and race, a higher VOmax was associated with a higher RMR (β = 68.2 kcal/day per L/min, P < 0.01) and 24-h EE (β = 62.2 kcal/day per L/min, P < 0.05) and including additional adjustment for energy intake higher AFT (β = 66.1 kcal/day per L/min, P = 0.01). Neither SMR (P > 0.2) nor SPA (P > 0.8) were associated with VOmax. VOmax at baseline did not predict follow-up weight after adjustment for baseline weight, follow-up time, sex, and race (P > 0.4).

CONCLUSION

VOmax is associated with measures of EE including 24-h EE, RMR and DIT implying a common mechanism regulating the energetics of skeletal muscle during exercise and thermogenesis. However, this did not translate to VOmax as a predictor of weight change.