Obese adolescents are at risk of becoming obese adults, which in turn places them at a higher risk of early diabetes and other chronic conditions. And exercise is an important means of both improving their general health as well as helping them with weight loss. But what kind of exercise is best? Would it be better to encourage aerobic exercises such as swimming or running, or would resistance training such as weight lifting be more effective?
Canadian researchers, led by Dr. Ronald J. Sigal of the University of Calgary in Alberta, Canada investigated this question by studying the effects of both types of training on over 300 obese adolescents between the ages of 14 and 18.
All the participants were given dietary counseling, and prescribed a diet with a 250 calorie deficit compared to a weight maintaining diet. Then, they were randomly assigned to one of four groups for 22 weeks: aerobic training; resistance training; combined aerobic and resistance training; and a non-exercising control group. At the beginning and end of the study period, the investigators measured the percent of body fat to see which of the groups had lost the most. They also measured the waist circumference as an indication of abdominal body fat, which is linked to increased risk of diabetes.
The non-exercising control group lost 0.3 percent of their initial body fat; the aerobic training group lost 1.1 percent; and the resistance-training group lost 1.6 percent; the combined training group lost 1.4 percent. Waist circumference decreased the most in the combined training group by 4.1 cm (about 1.5 inches).
Overall, the researchers found that all three exercise groups reduced their body fat and waist circumference. Further, in those participants who were most adherent to their training protocols, the combined training was the most effective in causing loss of body fat and waist circumference.
ACSH s Dr. Ruth Kava commented: While this was a relatively short study, it s importance lies in the information that either type of exercise or a combination of the two can be effective for obese adolescents. The real challenge, however, is motivation. The more adherent participants had better results. It will be interesting to see if these individuals will continue their training regimens and continue to lose body fat.