You probably know that aerobic training burns fat and resistance training builds muscle and helps sculpt the body. But if you want to lose weight, you have to rev up your metabolism so that it burns extra calories even when you’re not doing anything more strenuous than scanning through the TV channels with your remote. And research shows the best way to do that is by lifting weights.

A recent study reported in Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine, found that when subjects engaged in only three days of weight training a week they experienced significantly improved metabolic rates.

To test the effectiveness of the training, the study subjects were kept for 23 hours in a specially designed room that measured the amount of oxygen they inhaled and the amount of carbon dioxide they exhaled. Those measurements were used to calculate metabolic rates and daily energy expenditures. The subjects, slightly overweight and sedentary men and women in their early 20s, were tested prior to beginning the research project. Half the subjects then completed a six-month weight-training program while the other half did no exercise.

After six months, the weight-lifting group significantly improved their previous resting and sleeping metabolic rates—and their metabolic rates were also significantly higher than those of the group that did no training.