Impact of downhill running on body composition and energy expenditure
Résumé
We aimed to compare the effects of 8-week eccentric versus concentric exercise training in rats on body composition and energy expenditure, since these parameters have not been fully investigated. Animals were assigned to group 1) control, 2) +15% uphill-running slope (CON), 3) -15% downhill- running slope (ECC15, iso-power output) or 4) -30% downhill-running slope (ECC30, iso-VO2). Total body mass increased in all groups over the 8 weeks. A significant gain in fat mass was only observed for control group (20.71±1.99g) compared to CON (-4.8±6.18g); ECC15 (0.6±3.32g) and ECC30 (2.6±6.01g). A gain in lean mass was mainly seen for ECC15 (88.9±6.85g, p=0.09) and ECC30 (101.6±11.07g, p=0.02). Basal metabolic rate increased for all running groups. Thereby, the impact of training on lean mass is enhanced with ECC30 compared to CON, and adaptations are still observed for lower VO2 (ECC15). Thus low intensity eccentric exercise training could be part of body composition regulation strategies.