ROSS, R., and I. JANSSEN. Physical activity, total and regional obesity: dose-response considerations. Med. Sci. Sports Exerc., Vol. 33, No. 6, Suppl., 2001, pp. S521–S527.
Purpose: This review was undertaken to determine whether exercise-induced weight loss was associated with corresponding reductions in total, abdominal, and visceral fat in a dose-response manner.
Methods: A literature search (MEDLINE, 1966–2000) was performed using appropriate keywords to identify studies that consider the influence of exercise-induced weight loss on total and/or abdominal fat. The reference lists of those studies identified were cross-referenced for additional studies.
Results: Total fat. Review of available evidence suggested that studies evaluating the utility of physical activity as a means of obesity reduction could be subdivided into two categories based on study duration. Short-term studies (≤16 wk, N = 20) were characterized by exercise programs that increased energy expenditure by values double (2200 vs 1100 kcal·wk-1) that of long-term studies (≥26 wk, N = 11). Accordingly, short-term studies report reductions in body weight (−0.18 vs −0.06 kg·wk-1) and total fat (−0.21 vs −0.06 kg·wk-1) that are threefold higher than those reported in long-term studies. Moreover, with respect to dose-response issues, the evidence from short-term studies suggest that exercise-induced weight loss is positively related to reductions in total fat in a dose-response manner. No such relationship was observed when the results from long-term studies were examined. Abdominal fat. Limited evidence suggests that exercise-induced weight loss is associated with reductions in abdominal obesity as measured by waist circumference or imaging methods; however, at present there is insufficient evidence to determine a dose-response relationship between physical activity, and abdominal or visceral fat.
Conclusion: In response to well-controlled, short-term trials, increasing physical activity expressed as energy expended per week is positively related to reductions in total adiposity in a dose-response manner. Although physical activity is associated with reduction in abdominal and visceral fat, there is insufficient evidence to determine a dose-response relationship.
School of Physical and Health Education, Queen’s University, Ontario, CANADA
Submitted for publication January 2001.
Accepted for publication March 2001.
Proceedings for this symposium held October 11–15, 2000, Ontario, Canada.