We examined the effects of three exercise training interventions on total physical activity energy expenditure (PAEE) or nonexercise PAEE in a randomized controlled trial where sedentary, overweight, and obese men and women were assigned to inactive control, low-amount/moderate-intensity, low-amount/vigorous-intensity, or high-amount/vigorous-intensity aerobic exercise.
To measure PAEE, triaxial RT3 accelerometers were worn by subjects for 7 d at the beginning and end of an 8-month exercise intervention. In total, 50 subjects (control, n = 8; two low-amount groups, n = 28; high-amount group, n = 14) had usable PAEE data collected at both time points.
At baseline, subjects had an average age of 53.2 yr, had a body mass index of 29.7 kg·m−2, and a relative peak V˙O2 of 28.7 mL·kg−1·min−1. There were no significant differences between groups at baseline. After the intervention, average change in total PAEE was 8.4 ± 20.9 kJ·h−1 for controls, 58.6 ± 20.9 kJ·h−1 for the two low-amount groups, and 138.1 ± 33.5 kJ·h−1 for the high-amount group (means ± SE). The high-amount group experienced a significantly greater increase in total PAEE compared with the controls (P = 0.02). As expected, total PAEE increased with increasing exercise volume. Average change in nonexercise PAEE was 8.4 ± 20.9 kJ·h−1 for control, 25.1 ± 20.9 kJ·h−1 for the low-amount groups combined, and 62.8 ± 29.3 kJ·h−1 for the high-amount group. There was no statistically significant difference in change of nonexercise PAEE among groups.
We conclude that in middle-aged overweight or obese subjects participating in an extended exercise intervention, total PAEE increased, and there was no compensatory decrease in nonexercise PAEE.
1Division of Cardiology, Duke University Medical Center, Durham, NC; 2Duke Clinical Research Institute, Duke University Medical Center, Durham, NC; and 3Duke Center for Living, Duke University Medical Center, Durham, NC
Address for correspondence: Cris A. Slentz, Ph.D., Division of Cardiology, Department of Medicine, DUMC Box 3022, Duke University Medical Center, Durham, NC 27710; E-mail: firstname.lastname@example.org
Submitted for publication September 2008.
Accepted for publication January 2009.