A new study shows that aerobic exercises are more effective at burning fat than resistance training or a combination of resistance and aerobic training.
The study, published in the Journal of Applied Physiology, analyzed the body composition of overweight or obese adults without diabetes who took on one of three different exercise regimins. The researchers state that it is the largest randomized trial to have done so.
"Given that approximately two-thirds of adults in the United States are overweight due to excess body fat, we want to offer clear, evidence-based exercise recommendations that will truly help people lose weight and body fat," said Leslie Willis, lead author of the study and an exercise physiologist at the Duke University Medical Center.
234 overweight or obese adults were enrolled in the study. The participants were randomly assigned to either aerobic training, resistance training, or a combination of the two. Aerobic training consisted of approximately 12 miles per week of aerobic exercise, such as walking, running, or swimming. Resistance training consisted of lifting weights three days per week, lifting three sets of 8 to 12 repetitions. Participants assigned to the combined training completed both the aerobic and resistance training goals.
The results show that the participants assigned to the aerobic and combined training groups lost more weight than those who did resistance training only. Unsurprisingly, participants assigned to the resistance training group actually gained weight, with a corresponding rise in lean body mass.
Aerobic exercise alone was shown to be a more efficient way to lose body fat. Even though the combination group participants spent more time exercising, they did not significantly reduce fat mass over those in the aerobic group. The combination group did, however, see the largest decrease in waist circumference. The resistance group also did not see significant decreases in fat mass.
"No one type of exercise will be best for every health benefit," said Willis. "However, it might be time to reconsider the conventional wisdom that resistance training alone can induce changes in body mass or fat mass due to an increase in metabolism, as our study found no change."