Is hot yoga (like Bikram) safe?

Yoga practiced in rooms where the temperature is cranked up to more than 100 degrees has become popular, in part because practitioners believe it can help them sweat off calories and toxins and make them more flexible as they pose. But it's unclear whether hot yoga has more weight-loss benefits than other types of yoga, and it doesn't help you purge toxins. Even worse, it could be harmful.

First, people tend to overstretch their muscles and joints in the warmth, making them more susceptible to injuries. And while some research has shown that body temperatures stay in a safe range, one recent study found that hot yoga raised some folks' core body temps to 103 degrees, with one person's hitting 104 degrees. Even for healthy people, that could lead to headache, dizziness and dehydration; anyone with a heart condition should definitely steer clear.

Yoga itself is a wonderful form of exercise and an effective stress reliever, but it's safest to practice it at room temperature. If you do decide to try hot yoga, make sure you take frequent water breaks and stop if you begin to feel breathless or uncomfortable. Bottom line: If you really want to perspire, a good old-fashioned run, dance class, or other form of cardio is your best bet.

Roshini Rajapaksa, MD, Health's medical editor, is assistant professor of medicine at the NYU School of Medicine and co-founder of Tula Skincare.

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