Metabolic rate during and after aerobic exercise in post-obese and lean women
Shah, M.; Geissler, C.A.; Miller, D.S.
European Journal of Clinical Nutrition 42(6): 455-464
1988
ISSN/ISBN: 0954-3007 PMID: 3409854 Document Number: 320129
The effect of aerobic exercise (cycling on bicycle ergometer for four 10-min periods/ 60 to 80% max VO2) on energy expenditure after the activity was studied in 16 post-obese and 16 lean control women during 24 h and shorter periods. In addition, net energy expenditure during aerobic exercise was compared with that during prolonged mild activity (stepping for four 30-min periods at 12 steps/min). The measurements were made in a room respirometer. Aerobic exercise did not significantly stimulate the 24-h resting metabolic rate of the post-obese (3%, 50 kcal), or lean controls (2%, 30 kcal), nor was there any significant stimulation during shorter periods: during waking hours resting metabolic rate was slightly increased by 5% in the post-obese and lean controls. Sleeping expenditure remained the same in the post-obese and was decreased by 2% in the lean controls. All subjects found the aerobic exercise to be quite uncomfortable, yet in both groups the net cost was smaller than that of prolonged mild exercise which was acceptable (post-obese: aerobic 180 kcal, mild 250 kcal; lean controls: 220 kcal, 290 kcal). It is suggested that prolonged mild activity (e.g., as in walking frequently) is more appropriate in increasing energy expenditure as a means of preventing or controlling obesity. Total expenditure at each level of activity was also expressed as multiples of basal metabolic rate (BMR) calculated from FAO/WHO/UNU (1985) prediction equations and from measured sleep values. The results show that the equations overestimated BMR in the post-obese.