The Healthy Eating Aerobic and Resistance Training in Youth (HEARTY) study determined that the best exercise program for obese teens combines aerobic exercise with resistance training. The study, which was led by researchers at the University of Calgary and University of Ottawa, involved 304 overweight teens from ages 14 to 18 years in the Ottawa/Gatineau area. One group performed resistance training involving weight machines and free weights; the second group performed aerobic exercise on treadmills, stationary bikes, and elliptical machines; and the third combined aerobic and resistance training. A fourth group did no exercise training.
The youths in the three exercise groups were supervised by personal trainers and asked to train four times per week for 22 weeks at community-based facilities. Changes in body fat were measured using Magnetic Resonance Imaging (MRI) machines. According to a news release from the University of Calgary, Faculty of Medicine, each type of exercise notably reduced body fat, and all three exercise programs caused significantly more fat loss than in the diet-control group. Among the youths who completed at least 70% of the study’s exercise, the percentage of body fat decreased “significantly more in those who did combined aerobic and resistance exercise than in those who only did aerobic exercise,” writes co-principal researcher Glen Kenny, PhD.
Kenny adds, “Remarkably, among participants who completed at least 70% of the prescribed exercise sessions, waist circumference decreased close to seven centimeters in those randomized to combined aerobic plus resistance exercise, versus about four centimeters in those randomized to do just one type of exercise, with no change in those randomized to diet alone.”
A Science Daily news report notes that the researchers hope that the study will contribute to a national debate about childhood and teenage obesity, possibly leading to a consistent, long-term strategy on how to most efficiently deal with the problem. The Science Daily news report also notes that 80% of overweight youth usually continue to be obese as adults, adversely affecting the quality of their lives and contributing to chronic disease problems.
Sources: University of Calgary, Faculty of Medicine, Science Daily