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

Academic Article


  • 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·kg FFM-1·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.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Melanson EL; Sharp TA; Seagle HM; Horton TJ; Donahoo WT; Grunwald GK; Hamilton JT; Hill JO
  • Start Page

  • 1045
  • End Page

  • 1052
  • Volume

  • 92
  • Issue

  • 3