Citations 0
December 17, 2003

Effect of Exercise Intensity on Body Composition—Reply

Author Affiliations

Letters Section Editor: Stephen J. Lurie, MD, PhD, Senior Editor.

JAMA. 2003;290(23):3069. doi:10.1001/jama.290.23.3069-a

To the Editor: Dr Jakicic and colleagues1 concluded that vigorous exercise intensity was not superior to moderate exercise intensity for weight loss in a 12-month physical activity program with additional restriction in dietary fat and caloric intake.

To help explain this unexpected finding, we suggest that the intensity-dependent effect of physical activity on body composition should be taken into account. A higher intensity level of physical activity leads to a more pronounced shift in the relationship of fat mass with fat-free mass (specifically, skeletal muscle mass) with only minimal changes in body weight.2,3 Thus, the apparent lack of an effect of intensity may be due to higher postintervention fat-free mass in the individual who exercised vigorously. This potential benefit of higher exercise intensity could have been assessed with measurement of body composition.

First Page Preview View Large
First page PDF preview
First page PDF preview