What research shows about the aerobic intensity of yoga.
If you’re like a lot of runners, you’ve at least dabbled in yoga. While you probably have a vague sense that yoga is “a good workout,” you might have wondered about the specifics: Is yoga best on running or non-running days? How many calories does it burn? And is it enough of a cardiovascular workout to count as aerobic cross-training?
Some answers come from a review of previous research on the aerobic aspects of yoga that will be published in Medicine & Science in Sports & Exercise. Enette Larson-Meyer, Ph.D., of the Department of Family and Consumer Sciences at the University of Wyoming, examined 17 studies on intensity levels reached and energy expended during yoga sessions. Her findings suggest that, while some forms of yoga can provide moderate cardiovascular benefits, runners should best view yoga as a strength and flexibility complement to rather than a substitute for their primary sport.
There are, of course, many forms of yoga, from those that focus on breathing and feature mostly sitting postures to those that entail holding complex standing poses and moving quickly through a series of poses. Larson-Meyer’s survey found that there’s equally great variety in these sessions’ intensity. Most were found to have a score of 2 to 3 on what’s known as metabolic equivalent of task (MET), a system used to compare energy expended in various activities. A MET score of 1 is considered the baseline, and corresponds to sitting or otherwise being sedentary. A MET score of 3 means an activity has roughly the same energy expenditure as walking at a leisurely pace. Activities with a MET score of 2 to 3 are considered light activity.
A key exception was surya namaskar, or sun salutation (seen in the video below). This is a series of standing, lunging and other poses, done relatively quickly and usually repeated two to six times. Depending on how vigorously they’re done, sun salutations typically produce a MET score of 3 to 6, which is considered moderate activity. (By way of comparison, running at 9:00-per-mile pace has a MET score of 10.5, well into what’s considered vigorous activity). In one study Larson-Meyer reviewed, sun salutations were done vigorously enough to produce a MET score of 7.4, the equivalent of a walk-run combination averaging between 12:00 and 15:00 per mile.
Larson-Meyer’s findings support the conventional view that yoga isn’t a huge calorie burner. Given the MET scores Larson-Meyer found, a typical half-hour session might burn around 150 calories, or roughly the amount you would expend in walking a mile and a half in that time. In a practical sense, even more intense routines, such as a vigorous sun salutation, won’t match running for weight loss, given that you’re unlikely to do such a series of poses uninterrupted for an hour.
As for “hot yoga,” Larson-Meyer wrote, “Despite purported claims that a Bikram yoga session expends up to 1,000 [calories] in 90 minutes, the MET values of Bikram yoga, performed in hot room with 40% relative humidity, were within the same range as yoga practiced at room temperature.” In a hot classroom, your heart rate will be higher and your sweat losses greater because of the temperature, but your long-term caloric burn will still be relatively low.
Rebecca Pacheco, who guides the Runner’s World yoga videos and is the author of Do Your Om Thing, noted that the studies Larson-Meyer reviewed mostly looked at Hatha and Bikram yoga sequences. “There are so many different styles of yoga today, many of which are highly physical and blended with other forms of fitness,” Pacheco said. “The articles referenced for the study date back as far as 1965—before the advent of two of the most popular and vigorous styles, Power Yoga and Vinyasa Yoga.” Continue reading >>