Heat production and quantitative oxidation of nutrients by physical activity in humans.
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.
Thorbek
G
G
Royal Veterinary and Agricultural University, Copenhagen, Denmark.
Chwalibog
A
A
Jakobsen
K
K
Henckel
S
S
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
D004040:Dietary Carbohydrates; D004041:Dietary Fats