Long-term resistance training (RT) may result in a chronic increase in 24-h energy expenditure (EE) and fat oxidation to a level sufficient to assist in maintaining energy balance and preventing weight gain. However, the impact of a minimal RT program on these parameters in an overweight college-aged population, a group at high risk for developing obesity, is unknown.
Purpose: We aimed to evaluate the effect of 6 months of supervised minimal RT in previously sedentary, overweight (mean ± SEM, BMI = 27.7 ± 0.5 kg·m−2) young adults (21.0 ± 0.5 yr) on 24-h EE, resting metabolic rate (RMR), sleep metabolic rate (SMR), and substrate oxidation using whole-room indirect calorimetry 72 h after the last RT session.
Methods: Participants were randomized to RT (one set, 3 d·wk−1, three to six repetition maximums, nine exercises; N = 22) or control (C, N = 17) groups and completed all assessments at baseline and at 6 months.
Results: There was a significant (P < 0.05) increase in 24-h EE in the RT (527 ± 220 kJ·d−1) and C (270 ± 168 kJ·d−1) groups; however, the difference between groups was not significant (P = 0.30). Twenty-four hours of fat oxidation (g·d−1) was not altered after RT; however, reductions in RT assessed during both rest (P < 0.05) and sleep (P < 0.05) suggested increased fat oxidation in RT compared with C during these periods. SMR (8.4 ± 8.6%) and RMR (7.4 ± 8.7%) increased significantly in RT (P < 0.001) but not in C, resulting in significant (P < 0.001) between-group differences for SMR with a trend for significant (P = 0.07) between-group differences for RMR.
Conclusion: A minimal RT program that required little time to complete (11min per session) resulted in a chronic increase in energy expenditure. This adaptation in energy expenditure may have a favorable impact on energy balance and fat oxidation sufficient to assist with the prevention of obesity in sedentary, overweight young adults, a group at high risk for developing obesity.
1Department of Kinesiology & Health Education, Southern Illinois University, Edwardsville, IL; 2Center for Physical Activity and Weight Management, Energy Balance Laboratory, University of Kansas, Lawrence, KS; and 3Department of Exercise and Health Sciences, University of Massachusetts, Boston, MA
Address for correspondence: Erik P. Kirk, Ph.D., Department of Kinesiology & Health Education, Southern Illinois University, Box 1126, Edwardsville, IL 62026; E-mail: firstname.lastname@example.org.
Submitted for publication April 2008.
Accepted for publication November 2008.