A study of studies finds that yoga may fall short on daily physical activity guidelines
As seen in The Post and Courier on Oct. 10, 2016
If yoga is your activity of choice, it may not be enough to satisfy recommended guidelines for daily physical activity.
A systematic review, which is a study of studies, published in the American College of Sports Medicine’s journal in August analyzed data from 17 prior studies evaluating energy expenditures. It found that yoga poses tended to fall in the level of light to moderate activity.
Both ACSM and the American Heart Association recommend at least 30 minutes of moderate to vigorous activity on most days.
For probably three years, I struggled to fit yoga classes into my routines of running and strength training and finally gave up. If I did manage to get two or three sessions in a week (which most yogis consider minimal), something had to give: a run or two, or a gym session.
Classes, after all, tend to take an hour. Throw in getting to a studio, putting out a mat, listening to an instructor, then packing up, you’re talking at least 90 minutes. If I ran the same amount of time, I’d scorch about 1,300 calories and burn off as much or more stress than the class.
But I’m a life-long runner and probably biased. And I find running very “yogic” in itself.
I also noticed that people who relied primarily on yoga often struggled doing 10 push-ups thrown in a routine and were easily “gassed” doing cardio activities. Yogis might be able to do a headstand but struggle to curl 25 pounds or run a sub-9 minute mile.
So I asked Dr. Daniel Bornstein, an assistant professor of exercise science at The Citadel who is chairman of the physical activity section of the American Public Health Association, what he thought of the review.
“It sends a bad message,” says Bornstein. “The evidence remains inconclusive.”
As the review itself acknowledged, Bornstein found that the review had its limitations, namely on the sample sizes of studies. Most were small and, in all, totaled about 200 people. He added, too, that those in the studies tended to be young adults.
“The real take-home message of this review is that we don’t have enough data to draw any conclusions,” says Bornstein. “It’s a disservice that we can’t count yoga for daily energy expenditure because we don’t know conclusively that it’s not significant.”
He says that yoga, like any activity, features different styles and ability levels, which will affect energy expenditure.
That’s true. Running a 6-minute mile is entirely different than a 12-minute mile. More athletic “power yoga,” the cornerstone of the hugely popular Charleston Power Yoga, will require more energy than “gentle yoga.”
Bornstein, who after the interview was planning to run and do yoga, called yoga an “extraordinary form of exercise” but adds that the focus by Americans on the physical aspects of it is unfortunate and that yoga is a powerful tool in reducing stress.
For those who do want to find what activities will help them reach goals of exercising moderately or vigorously, Bornstein suggest people compare them in “The Compendium of Physical Activities,” which was originally developed at the University of South Carolina while Dr. Barbara Ainsworth was there. (Ainsworth is now at Arizona State.)
“It’s an underutilized resource,” says Bornstein, of the compendium, which was originally published in 1993 and last updated in 2011.
The update provides energy expenditures on more than 800 levels of activities. It uses a scientific formula known as METS or “Metabolic Equivalent of Task.”
The compendium is used globally to quantify the energy cost of physical activity in adults for surveillance activities, research studies, and, in clinical settings, to write exercise recommendations and to assess energy expenditure in individuals.
In the updated version, playing a board game requires 1.5 METS.
Various forms of yoga range from 2.5 for hatha yoga to 4.0 for power yoga. By comparison, resistance training ranges for 3.5 to 6.0 METS. Running a 6-minute mile scores 14.5 while a 12-minute mile gets an 8.3.
Ultimately, the yoga review helps underscore that people would benefit from a mix of activities and that none are individually complete for physical fitness.
Reach David Quick at 937-5516.