Yoga – that touchy-feely, non-competitive, om-chanting exercise – can kill you. Well, that may be extreme, but new scientific studies have found that some yoga positions can cause stroke, paralysis and serious muscle damage. But, it can also lead to a healthier and happier life if done right.
New York Times Pulitzer-prize-winning science writer William Broad joined the show to talk about his new book, "The Science of Yoga," and to discuss the pluses and minuses of the popular exercise.
Among other physical risks, Broad said that certain neck poses, like shoulderstand and plow pose, can cause strain on the neck that tweaks an artery and causes blood clots to form, which can lead to a stroke.
"The science is really clear," he said. "You can tweak this artery that winds its way through this bony labyrinth through the vertebrae, and tear the delicate inner lining. If that happens it can swell, blood clots can form, and next thing you know those blood clots are going to the brain."
Broad noted that in response, there's a growing reform movement of yoga practitioners who avoid these poses altogether, or suggest alternate ways to perform the stunts.
"The younger people are extremely cautious on these uses. They use blankets for shoulder stands and plow, and recommend you use them to take some of the stress off the neck," he explained.
In addition, Broad said studies show that yoga doesn't provide enough heart pounding to give you the weekly recommended aerobic activity, contrary to the way yoga is often marketed.
"Clearly a lot of the claims are inflated, and some of the most inflated claims center on this mythical, aerobic quality of yoga," he said. "It turns out that no matter how hard or how fast you do yoga, you just don't get the heart pounding 'oomph' you need to fulfill even the most basic of aerobic guidelines. Yoga, in general, tends to be gentle. That's a great thing."
Despite his criticism of the practice, Broad calls himself a "yoga booster, not a yoga basher." His book questions inflated claims about yoga, but his research also reinforces the idea that yoga is incredibly relaxing and good for you.
"There have been beautiful studies showing how it releases natural chemicals in the brain; lift moods and outlook. Yoga stirs hormones that can revitalize your sex life," he continued. "The bottom line, and probably the most important thing and the reason that so many people go to yoga, is that it clearly improves overall health."
William Broad, author of the new book "The Science of Yoga."
Read an excerpt from "The Science of Yoga":