Aerobics combined with resistance training best exercise for fat teens

A new study has claimed that combining aerobic exercise with resistance training can battle the "epidemic" of obesity in teenagers.

The Healthy Eating Aerobic and Resistance Training in Youth (HEARTY) study, which was led by researchers at the University of Calgary and University of Ottawa, involved 304 overweight teens in the Ottawa/Gatineau area between the ages of 14 to 18, where all were given the same four weeks of diet counseling to promote healthy eating and weight loss before being randomly placed into four groups.

While the first group performed resistance training involving weight machines and some free weights, the second performed only aerobic exercise on treadmills, elliptical machines and stationary bikes, the third underwent combined aerobic and resistance training, and the last group did no exercise training.

In the overall study population, each type of exercise reduced body fat significantly and similarly. All three exercise programs caused significantly more fat loss than in the diet-only control group. Among youths who completed at least 70 per cent of the study's exercise sessions, the percentage of body fat decreased significantly more in those who combined aerobic and resistance exercise than in those who only did aerobic exercise, said co-principal researcher Dr. Glen Kenny.

Remarkably, among participants who completed at least 70 per cent 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, Kenny added.

Researchers hope that the study would contribute to a national debate about childhood and teenage obesity, potentially leading to a consistent, long-term strategy on how to best deal with the problem.

The study is published in the Journal of the American Medical Association (JAMA) Pediatrics.