It sometimes seems there are just two kinds of exercisers in the world: those who throw around weights in the gym, and those who hit the roads (or treadmills) to enhance their aerobic fitness. Health authorities eagerly endorse both--an easy call given the country’s rampant obesity crisis. Indeed, health experts recommend that we include both strength and aerobic training in our weekly exercise regimen.
When it comes to weight loss, however, running and similar activities have held favour over resistance training. Simply put, they burn more calories per hour. According to the Compendium of Physical Activities, even slow running counts as “vigorous” activity, while most strength training falls into the “moderate” category. Given that we are advised to get either 150 minutes of moderate activity each week, or 60 minutes of vigorous activity, you can see why so many people opt for running.
But a new study from a well-known lab at Arizona State University suggests that strength training burns roughly twice as many calories per minute as previously thought. “Relatively light resistance exercises are, in fact, vigorous-intensity activities,” the researchers conclude.
The study team believes that prior studies of calorie burn during resistance training were limited by an inappropriate energy-expenditure equation. Statisticians treated resistance training as if it were a slow, gradual activity like running or bicycling. The reality is that much strength training involves short, anaerobic bursts of power, followed by recovery periods.
In their experiment, the Arizona State researchers used two different equations to calculate the calorie burn of push-ups, curl-ups, lunges, and pull-ups: a traditional calculation and a newer one, more appropriate to anaerobic efforts. The calorie-burn differences were dramatic.
The calorie burn for push-ups, for example, increased from 4.1 calories per minute to 8.56 calories per minute. Curl-ups increased from 4.09 calories per minute to 7.29; lunges from 5.28 calories per minute to 9.33; and pull-ups from 4.03 calories per minute to 9.95.
The new calculation means that push-ups, lunges, and pull-ups qualify as vigorous activity. None of the three reached this level with the old calculation.
In the experiment, 12 healthy young men performed one of the four exercises up to 20 times in 60 seconds. They then rested about five minutes before moving on to the next exercise. The entire workout included three sets of the four exercises, and took roughly 72 minutes. None could do 20 pull-ups in 60 seconds; the average was 10 pull-ups. One subject could not complete all the push-ups. All successfully completed the lunges and curl-ups.
“The results of our study seem to better represent this higher activity [of strength training],” the researchers state. “Our information can potentially be used to design more effective programs to elicit optimal results.”
The video shows a strength training session that uses bodyweight exercises similar to the ones in the study described above.