Exercise increases fat oxidation at rest independent of energy
balance, and unrelated to changes in lipolysis or body
composition.
Calles-Escandon, Jorge, Michael I. Goran, Maureen O'connell, K.
Sreekumaran Nair, And.
The Endocrinology, Metabolism and Nutrition Unit, Department of
Medicine, University of Vermont and the Sims Obesity/Nutrition
Research Center
APStracts 3:0045E, 1996.
The hypothesis whether exercise increases fat oxidation at rest
independent of changes in energy balance, body composition, and/or
lipolysis was tested in twenty one volunteers. After a period of
energy balance, volunteers were randomly allocated to one of 4
groups: control, overfed (OF), overfed and exercise (OF-EX) and
exercise (EX). OF and OF-EX were overfed 50% excess of energy balance
calories; OF-EX and EX spent 50% excess of energy balance calories
during daily exercise sessions. Exercise increased fat oxidation at
rest independent of dietary intake (OF-EX = +22 +/- 2.4, EX = +23 +/-
1.5 mg/min) and reduced carbohydrate oxidation (OF-EX = -49 +/- 6.2,
EX =-46 +/- 5.4 mg/min). Volunteers in the OF group had an increase
in carbohydrate oxidation (85 +/- 5.9 mg/min) and a decline in fat
oxidation (-33 +/- 1.4 mg/min). Protein oxidation did not change in
any group. These changes occurred without a direct relation with
changes in lipolysis and persisted even when expressed as a percent
or as an absolute equivalent of resting metabolic rate calories.
Thus, exercise, independent of changes in energy intake and body
composition and not related to changes in lipolysis, increases fat
oxidation at rest which may explain the beneficial effects of
exercise in weight loss programs.
Received 24 July 1995; accepted in final form 19 December 1995.
APS Manuscript Number E349-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96