We've long been told that a workout for losing weight has to involve strength training—because even while resting, muscle burns energy, raising our metabolisms, right?
But a new study calls that conventional wisdom into question (which I am a little too happy to hear, because I find strength training boring beyond belief . . ). Researchers at Duke University took a group of overweight or obese people and assigned them to three different groups: One group did only a weight-lifting workout, another did only aerobic training, and a third did a workout involving both aerobics and weights. The exercise sessions were supervised.
At the end of the study period, participants had their body composition analyzed, and researchers found that the groups that did cardio lost more weight than the group that did strength training alone. What's more, the group that did cardio and strength training did not lose more body mass or fat mass than the cardio-only group, despite having spent almost twice as much time exercising.
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 H. Willis, MS, an exercise physiologist at Duke Medicine and the study's lead author, said in a statement, adding: "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."
Now, these researchers certainly are not saying that weight training isn't beneficial—it can prevent bone loss and muscle atrophy, two very important benefits as we age.
But when your primary goal is weight loss, don't think you can skimp on the cardio. And when you're trying to shed pounds and are short on time, the most efficient workouts for losing weight are aerobic ones.
Balancing time commitments against health benefits, our study suggests that aerobic exercise is the best option for reducing fat mass and body mass," said Cris A. Slentz, PhD, a Duke exercise physiologist and study co-author, in a statement. "It's not that resistance training isn't good for you; it's just not very good at burning fat."
More About the Best Weight Loss Programs and Workouts: