title: Heat production and quantitative oxidation of nutrients by physical activity in humans.
abstract: The effect of physical activity on heat production and oxidation of nutrients was measured by means of indirect calorimetry. The experiment included 6 male and 4 female healthy subjects who, during a 24-hour stay in the respiration chambers, performed, in the morning and afternoon, 15 min cycling with the total work of 6,750 kg m. Experiments were repeated twice (3- to 4-week interval) showing no differences between the gas exchange in the morning and afternoon and between first and second experiment. The gas exchange during cycling was about 4 times higher than during basal periods. The identical work of 66.2 kJ by cycling caused on average a heat increment of 309 kJ, yielding the mean energetic efficiency for the performed work of 0.22. The activity caused an increment of 11.5 g oxidized carbohydrate and 2.6 g oxidized fat.
authors.affiliation: Royal Veterinary and Agricultural University, Copenhagen, Denmark.
authors.forename: G
authors.initials: G
authors.lastname: Thorbek
authors.forename: A
authors.initials: A
authors.lastname: Chwalibog
authors.forename: K
authors.initials: K
authors.lastname: Jakobsen
authors.forename: S
authors.initials: S
authors.lastname: Henckel
mesh_terms: D000328:Adult; D001642:Bicycling; D001833:Body Temperature Regulation / Q000502:physiology*; D004032:Diet; D004040:Dietary Carbohydrates / Q000378:metabolism; D004041:Dietary Fats / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D011659:Pulmonary Gas Exchange / Q000502:physiology
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats