You’re crammed in a 100-degree room next to 50 gasping, perspiring men and women, twisting your body into impossible pretzel-like contortions. Sweat drips off your bare flesh and onto the soaked and spongy mat beneath you, forming a small puddle. The room is suffocating, and a wave of dizziness passes over you. This scenario may sound like a form of cruel and unusual torture, but it just so happens to be one of the hottest fitness trends—hot yoga.
A form of yoga typically consisting of 26 poses and two breathing exercises practiced in a room heated to 95-100 degrees with 40 percent humidity, hot yoga has lured a robust clientele hailing from all corners of the globe. It’s easy to see why: hot yoga promises a number of compelling health benefits, alleging to cure everything from back pain to high blood pressure to anxiety. And, a 90-minute session is purported to scorch a whopping 1,000 calories, all while flushing out toxins and increasing flexibility.
“Hot yoga is provocative,” says Sat Bir Singh Khalsa, Ph.D., assistant professor of medicine at Harvard Medical School, certified Kundalini Yoga instructor and author of the book Your Brain on Yoga. “You’re in this hot environment, pushing yourself to your physical limits…it’s this whole unique, provocative scene, and I think people are drawn to that.”
But does hot yoga really stand up to its claims, or is this sweat-drenched practice too good to be true? We untangle the truth behind hot yoga’s purported benefits.
Rumor: Hot Yoga provides a harder cardio workout than regular aerobic exercise.
The heated environment in hot yoga classes is thought to speed up heart rate, giving you a more rigorous aerobic workout. But can a hot yoga session replace more traditional forms of cardio?
In a groundbreaking July 2013 study conducted by the American Council on Exercise (ACE), researchers examined the effects of hot yoga on heart rate and core temperature. The findings? Hot yoga might not be as hard as you think, says Cedric Bryant, Ph.D., FACSM, Chief Science Officer for ACE.
“Despite the subjects’ perceiving the workout to be so much more challenging, in terms of the heat’s effect on heart rate and core temperature, it really wasn’t much different than a class performed in a thermally neutral environment,” Bryant says.
In other words, individuals don’t experience much of a spike in heart rate between a regular yoga class and a hot yoga class. So although the heat makes the workout feel more challenging, you’re not necessarily working any harder.
Rumor: Hot Yoga offers stress relief.
Stress reduction is one of the largest benefits of any yoga practice, heated or otherwise, Khalsa says. “Stress reduction is extremely valuable because it allows people to cope with their lives on a day to day basis, improving their overall wellbeing,” he says. “What’s more, chronic stress is a very powerful risk factor for most major diseases.”
Rumor: Hot Yoga cleanses your body of toxins.
The combination of twisting postures and sweat in Hot Yoga is thought to help the body flush away toxins and waste products. However, this notion of toxin release is vague and unfounded, Khalsa says. “From a physiological perspective, no one knows what ‘flushing out toxins’ actually means. What’s being released, what’s being cleansed, what’s being purified…none of this is really clear,” Khalsa says.
Rumor: Hot Yoga increases flexibility.
Hot yoga promises to loosen the muscles and increase flexibility. Experts agree that there’s no denying this claim: “This is probably the biggest benefit we see,” Bryant concurs. “The heat certainly helps the individual warm up the muscles, joints and ligaments so that you’ll be more effective with any type of flexibility or stretching type exercises. Over time, you should see improvements in flexibility.”
Rumor: Hot Yoga delivers a massive calorie burn.
Some hot yoga classes claim to torch 1,000 calories in a single 90-minute session. “That is a gross exaggeration,” Bryant says. “Most disciplines of yoga—from your mildest forms to your most intense power yoga classes—will have a modest calorie burn ranging from about 3 to 7 calories per minute.” So if you’re assuming that your Bikram class is burning the caloric equivalent of a cheeseburger and fries, you want might to reevaluate your calorie counting.
Rumor: Hot Yoga is a great tool for weight loss.
Reality: True and false.
As we’ve seen, from a calorie-burn perspective, hot yoga isn’t as effective as cardiovascular-intensive forms of exercise like running or cycling. However, yoga may lead to weight loss indirectly—by influencing practitioners to make better food choices. “What comes out of a yoga practice is the development of mind-body awareness,” Khalsa says. “When you practice yoga after a while, you smoke a cigarette or excessively drink or overeat, and you are very keenly aware of the effect of that on your body. Yoga, in that sense, is a practice that can encourage people to desire better behavioral choices and lifestyle choices.”
So will practicing yoga alone cause you to shed pounds? Not necessarily. But it may cultivate mindful eating, improve quality of sleep and combat stress, which will in turn lead to weight loss. At the end of the day, both Khalsa and Bryant say that the benefits of a hot yoga practice (increased flexibility, stress relief, etc.) vastly outweigh the relative negatives (namely, lack of calorie burn).
“There are so many reasons why one should be physically active other than weight loss. If it’s something you really enjoy and it provides other benefits, there’s no reason you should give it up,” Bryant says.
Khalsa agrees: “Yoga is a practice which can encourage people to desire better behavioral choices and lifestyle choices. It’s basically a way of maintaining your body in its optimum functioning state. And that leads to better well being, better quality of life and, ultimately, better health.”