Nonexercise energy expenditure and physical activity in the Midwest Exercise Trial 2.
OBJECTIVE
This study aimed to examine compensatory changes in nonexercise energy expenditure (NEEx) and nonexercise physical activity (NEPA) in response to an aerobic exercise training program.


METHODS
Ninety-two overweight/obese (body mass index, 25-39.9 kg·m) sedentary young adults (18-30 yr) completed a 10-month randomized clinical efficacy trial of aerobic exercise 5 d·wk at either 400 kcal per session (n = 37), 600 kcal per session (n = 37), or control (n = 18). Total daily energy expenditure (TDEE) and resting metabolic rate (RMR) were measured at months 0 and 10. NEPA was measured by an accelerometer at months 0, 3.5, 7, and 10. NEEx was calculated by the following formula: [(total daily energy expenditure × 0.9) - RMR] - net EEEx (EEEx-RMR). Mixed modeling was used to examine differences between groups (group effect), within groups (time effect), and group-time interaction for NEEx and NEPA.


RESULTS
Within the exercise groups, there were no significant effects (all P > 0.05) of group, time, or group-time interaction for NEPA. In addition, there were no significant within- or between-group differences for change in NEEx. However, activity counts per minute were significantly higher (P < 0.001) in the 600-kcal-per-session group (346 ± 141 min·d) versus controls (290 ± 106 min·d) at month 7 and significantly higher (P < 0.001) in both the 600-kcal-per-session (345 ± 163 min·d) and 400-kcal-per-session groups (317 ± 146 min·d) versus controls (277 ± 116 min·d) at 10 months.


CONCLUSIONS
A 10-month aerobic exercise training program in previously sedentary, overweight and obese young adults was not associated with compensatory decreases in NEEx or NEPA. Results suggest that overweight and obese individuals do not become less physically active or spend more time in sedentary pursuits in response to exercise.
1Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS; 2Health, Physical Education, and Recreation, Augustana College, Sioux Falls, SD; and 3Institute for Measurement, Methodology, Analysis, and Policy, Texas Tech University, Lubbock, TX.
Erik A
EA
Willis
Stephen D
SD
Herrmann
Jeffery J
JJ
Honas
Jaehoon
J
Lee
Joseph E
JE
Donnelly
Richard A
RA
Washburn
D061725:Accelerometry; D000293:Adolescent; D000328:Adult; D004734:Energy Metabolism; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000503:physiopathology* / Q000628:therapy*; D050177:Overweight / Q000503:physiopathology* / Q000628:therapy*; D057185:Sedentary Behavior; D012737:Sex Factors; D055815:Young Adult