Excess post-exercise oxygen consumption after different moderate physical activities in a healthy female population

Aim. In the recovery period after exercise there is an increase in oxygen uptake defined as excess post-exercise oxygen consumption (EPOC). The magnitude of EPOC after aerobic exercise may depend on duration and intensity of exercise, on type of exercise (split exercise or continuous sessions) and on subjects' training status and sex. Weight loss can be achieved by increasing energy expenditure (EE). EPOC causes an increase in caloric burn during the recovery period, to be taken into consideration in relation to energy balance and weight loss. It is not clear whether various modes of aerobic exercise affect EPOC differently. The aim of this study was to evaluate the acute effects of moderate intensity of cycling (C), treadmill (T), arm crank (A) exercises, cross-training exercise (CT) and moderate to vigorous intensity activities of daily living (ADL) on EPOC. Methods. Six young moderately active females (age, 24.2 +/- 0.8 yr; BMI, 21.5 +/- 2.4 kg/m(2); RMR, 1288 +/- 78.2 kcal/day; (V) over dotO(2peak) cycle ergometer, 40.3 +/- 4.3 mL/kg/min; (V) over dotO(2peak) treadmill, 40.9 +/- 6.9 mL/kg/min; (V) over dotO(2peak) arm ergometer, 22.2 +/- 3.4 mL/kg/min) participated in the study over a three-week period. In the first week subjects filled a Baecke questionnaire on habitual physical activity, underwent a resting metabolic rate (RMR) measurement and 3 incremental tests to exhaustion ((V) over dotO(2peak) at treadmill, cycle ergometer and arm ergometer). In the second and third week they completed five bouts of 30 min of exercise at 60 % of (V) over dotO(2peak) separated by 48 hours of rest: a continuous C, T, A, a combined running, cycling and arm crank (CT) for 10 min each and ADL (3-6 METs). Before (30 min pre) and after (2 hours post) each exercise bout a RMR measurement was carried out in a sitting position with indirect calorimetry (K4b(2), Cosmed, Italy). A MANOVA and a repeated measures ANOVA were used for data analysis. Results. EPOC ranged in between 7% and 17% of Total Energy Expenditure. EPOC magnitude was also higher for CT than all the others training modes, even not significantly. O-2 consumed during and after T and C was significantly higher than A when normalized to the pre-exercise levels (P<0.001). The higher oxygen consumption ((V) over dotO(2)) during exercise was found for T and C, significantly higher when compared with CT and ADL (P<0.01); on the contrary A was significantly lower than all the other training modes (P<0.001). The respiratory exchange ratio (QR) was significantly lower for T when compared with C during exercise (P<0.01). Differences were detected during exercise between training modes for energy source utilization: fat utilization was significantly higher for T when compared with all the other training modes (P<0.01), otherwise carbohydrates utilization was significantly higher for C when compared with T, A, and ADL (P<0.01). There were no significant differences between training modes for energy sources during the 2-hour post-exercise, although T allowed for a greater fat utilization. Conclusion. This study shows that 30 min of all exercise modes provided an increase of EE for the first 2-hour after exercise. This study shows that T can be considered the best weight loss exercise when compared with all the other training modes measured. Our results indicate that separating a continuous 30 min exercise into three 10 min exercises will elicit an equivalent EPOC; this could be beneficial for subjects with a low fitness level who are unable to perform one long-bout of exercise on the same ergometer. The equivalent EE during and after exercise between activities of daily Living and the other training modes underlines the importance of an active lifestyle, especially when weight loss is concerned.