Aerobic Exercise More Effective in Reducing Obesity-Related Problems in Adolescent Girls

Although changes in diet and physical activity are the typical treatments for obesity, a recent study conducted by University of Pittsburgh School of Medicine found that the type of physical activity matters. Without any changes in diet, aerobic exercise is more effective than resistance exercise in reducing obesity-related risk factors for obese adolescent girls.

Over the course of three months, researchers compared the effects of aerobic and resistance exercise on insulin sensitivity and body fat distribution. The experiment randomly assigned sedentary, obese black and white girls aged 12 to 18 to one of three groups: an aerobic exercise group, a resistance exercise group, or a non-exercise control group. For three hour-long sessions a week, participants in the aerobic exercise group exercised on the treadmill and/or the elliptical, while participants in the resistance exercise group performed a series of whole body weight exercises. The control group was instructed not to perform any structured physical activity. To maintain their body weights, all participants were told to follow a diet consisting of 55-60% carbohydrates, 15-20% protein, and 25-30% fat.

Although there was a significant loss of body fat percentage in both exercise groups compared to the control group, only the aerobic exercise group had significant reductions in obesity-related risk factors. Researchers found that the girls who performed aerobic exercises lost a significant percent of abdominal and liver fat, and showed significant improvements in insulin sensitivity and cardiorespiratory fitness. The results suggest that when caloric intake is not restricted, aerobic exercise is most beneficial for decreasing the risk of fatty liver disease, type 2 diabetes, and metabolic syndrome.

Read more at: http://ajpendo.physiology.org/content/ajpendo/early/2013/09/11/ajpendo.00285.2013.full.pdf

Interestingly enough, the same researchers from University of Pittsburgh had previously reported that increasing any form of physical exercise, whether aerobic or resistance exercise, decreased abdominal and liver fats and increased insulin sensitivity in obese adolescent boys. While reasons for the gender differences remain unclear, the study’s findings emphasize that exercise routines should be personalized to better accommodate individual needs.