Effect of exercise intensity on 24-h energy expenditure and nutrient oxidation

J Appl Physiol (1985). 2002 Mar;92(3):1045-52. doi: 10.1152/japplphysiol.00706.2001.


The aim of this study was to determine the effects of exercise at different intensities on 24-h energy expenditure (EE) and substrate oxidation. Sixteen adults (8 men and 8 women) were studied on three occasions [sedentary day (Con), a low-intensity exercise day (LI; 400 kcal at 40% of maximal oxygen consumption) and a high-intensity exercise day (HI; 400 kcal at 70% of maximal oxygen consumption)] by using whole room indirect calorimetry. Both 24-h EE and carbohydrate oxidation were significantly elevated on the exercise days (Con < LI = HI), but 24-h fat oxidation was not different across conditions. Muscle enzymatic profile was not consistently related to 24-h fat or carbohydrate oxidation. With further analysis, it was found that, compared with men, women sustained slightly higher rates of 24-h fat oxidation (mg x kg FFM(-1) x min(-1)) and had a muscle enzymatic profile favoring fat oxidation. It is concluded that exercise intensity has no effect on 24-h EE or nutrient oxidation. Additionally, it appears that women may sustain slightly greater 24-h fat oxidation rates during waking and active periods of the day.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Calorimetry, Indirect
  • Carbohydrate Metabolism*
  • Circadian Rhythm*
  • Energy Metabolism*
  • Exercise / physiology*
  • Fats / metabolism*
  • Female
  • Humans
  • Male
  • Muscle, Skeletal / enzymology
  • Oxidation-Reduction
  • Physical Endurance / physiology*
  • Sex Characteristics


  • Fats