Excess Postexercise Oxygen Consumption in Untrained Males

Abstract

0189 The contributions of muscle mass to excess postexercise oxygen consumption (EPOC) are unknown. PURPOSE: The purpose of this study was to compare the magnitude and duration of EPOC following a continuous 200 kcal bout of upper-body exercise (UBE) and a continuous 200 kcal bout of lower body exercise (LBE). METHODS: Ten untrained male subjects (25.7 ± 5.83 yrs; arm VO2 peak: 2.2 ± 0.25 L/min, 21.5 ± 4.35 ml/kg/min; leg VO2 peak: 3.1 ± 0.38 L/min, 30.7 ± 7.79 ml/kg/min), on separate days (min 48 hrs between days) and in counterbalanced order, performed the two bouts of exercise at 60% of mode-specific VO2 peak. Subjects reported rested, fasted, and performed a 30-minute seated baseline test prior to exercise to determine resting metabolic rate. Postexercise VO2 was continuously monitored until baseline was reestablished. RESULTS: EPOC magnitude and duration were both significantly greater (p<0.05) following LBE (2.93 L O2 ± 1.4; 16.5 min ± 7.4) compared to UBE (1.89 L O2 ± 0.7; 11.5 min ± 6.1). CONCLUSIONS: These data indicate that leg exercise at moderate intensity elicits both a significantly greater magnitude and duration of EPOC compared to arm exercise of the same mode-specific relative intensity and equal exercise energy expenditure. It appears that involved muscle mass may be a key determinant of the EPOC response.