Purpose: Abdominal and lower body fat mass tissues exhibit particular metabolic profiles at rest and during exercise. However, data are missing in normal weight women during exercise. The purpose of this study was to investigate the effect of low (LA/LB) and high (HA/LB) abdominal to lower body (A/LB) fat mass ratio on metabolic and hormonal responses during exercise in premenopausal normal weight women.
Methods: After preliminary testing (V˙O2max and body composition assessment), substrate oxidation (RER, lipid, and carbohydrate oxidation rates), metabolic response (glycerol, free fatty acids, and glucose), and hormonal response (insulin, growth hormone, atrial natriuretic peptide, adrenaline, and noradrenaline) were determined during exercise (45 min at 65% of V˙O2max) in 21 premenopausal normal weight women (10 HA/LB women vs 11 LA/LB women).
Results: Waist circumference was significantly higher in HA/LB women compared with LA/LB women (P < 0.01). No difference in other anthropometric characteristics, V˙O2max, and resting blood values was observed between the two groups. LA/LB subjects exhibited greater lipid oxidation rates compared with HA/LB women during exercise (P < 0.01). This occurred with lower plasma insulin (P < 0.05) and glucose (P < 0.05) concentrations and higher plasma free fatty acids (P < 0.05), glycerol (P < 0.05), growth hormone (P < 0.05), and atrial natriuretic peptide levels (P < 0.01) during exercise in the LA/LB group compared with the HA/LB group.
Conclusions: The present study demonstrated that LA/LB women exhibited an increase in whole-body lipid mobilization and use during exercise compared with HA/LB counterparts. This greater reliance on lipid as fuel metabolism during exercise could be explained by substrate availability and metabolic and hormonal responses. It appeared that LA/LB women exhibited greater metabolic flexibility during an exercise bout of 45 min at 65% of V˙O2max on cycle ergometer.
1Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological Conditions, Blaise Pascal University, Clermont-Ferrand, FRANCE; 2INSERM U698, Bioengineering for Cardiovascular Imaging and Therapy, Paris, FRANCE; 3Paris University 13, IUT of Saint-Denis, FRANCE; 4Laboratory Movement Sport and Health Sciences, EA 1274, UFR APS, University of Rennes 2, Rennes Cedex, FRANCE; 5Department of Sport Medicine and Functional Explorations, Clermont-Ferrand University Hospital, G. Montpied Hospital, Clermont-Ferrand, FRANCE; 6INRA, UMR 1019, Clermont-Ferrand, FRANCE; 7University Clermont 1, UFR Medicine, Clermont-Ferrand, FRANCE; and 8CRNH-Auvergne, Clermont-Ferrand, FRANCE
Address for correspondence: Nathalie Boisseau, Ph.D., Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological Conditions (AME2P), Blaise Pascal University, 24, Avenue des Landais, BP 26, 63171 Aubière Cedex, France; E-mail: Nathalie.Boisseau@univ-bpclermont.fr.
Submitted for publication September 2012.
Accepted for publication March 2013.