title: Effects of aerobic exercise on energy expenditure and nitrogen balance during very low calorie dieting.
abstract: Aerobic exercise in addition to severe caloric restriction was studied for its effects on resting energy expenditure (REE), weight loss, and lean tissue preservation in adult women. A formula diet providing 1.5 g protein and 0.5 g carbohydrate (CHO) per kilogram of ideal body weight daily (mean intake 720 kcal/d) was given to 12 overweight inpatients for 4 to 5 weeks. Six subjects remained sedentary (group 1), while the other six subjects (group 2) performed supervised endurance exercise (a total of 27 hours at 50% of maximal oxygen uptake (VO2max) over 4 weeks). Lean tissue preservation was excellent in both groups and was unaffected by the group 2 exercise regimen. Weight loss over 4 weeks in the two groups did not differ (group 1, 6.9 +/- 0.7 kg; group 2, 6.5 +/- 0.7 kg). The VO2max was not increased after 4 weeks of exercise compared with controls. The resting oxygen consumption (rVO2) of both groups declined 10% (P less than .001) in the first seven days of dieting. Thereafter the rVO2 in group 1 remained stable, but a further 17% reduction occurred in group 2 (P less than .03) by the third week of exercise. The free triiodothyronine (fT3) concentration also fell more in group 2 (P less than .05), suggesting a relationship between fT3 and energy expenditure during severe caloric restriction. The ergometer exercise for up to two hours daily was well tolerated. The absence of either a training effect or accelerated weight loss in group 2 may be due to the limited duration (4 weeks) or intensity of the exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: General Clinical Research Center and Metabolic Unit, University of Vermont College of Medicine, Burlington.
authors.forename: S D
authors.initials: SD
authors.lastname: Phinney
authors.forename: B M
authors.initials: BM
authors.lastname: LaGrange
authors.forename: M
authors.initials: M
authors.lastname: O'Connell
authors.forename: E
authors.initials: E
authors.lastname: Danforth
mesh_terms: D020155:3-Hydroxybutyric Acid; D000328:Adult; D000332:Aerobiosis; D001481:Basal Metabolism; D001835:Body Weight; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D002149:Energy Intake; D004734:Energy Metabolism; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D006885:Hydroxybutyrates / Q000097:blood; D009765:Obesity / Q000178:diet therapy / Q000628:therapy*; D010101:Oxygen Consumption; D013963:Thyroid Hormones / Q000097:blood
chemical_list: D004040:Dietary Carbohydrates; D006885:Hydroxybutyrates; D013963:Thyroid Hormones; D020155:3-Hydroxybutyric Acid