How Does Hot Yoga Change Your Body?

Hot yoga is a generic term that covers any style of yoga class that takes place in a very warm and humid room. The best known hot yoga, the style synonymous with the term, is Bikram yoga, a system of 26 classic asanas taught in a space heated to 105 degrees Fahrenheit with approximately 40 percent humidity. Practitioners swear by hot yoga's healthful benefits, including improvements in flexibility, aerobic capacity and physical strength.

The warm room used for hot yoga classes allows tight muscles to release faster and stay loose throughout the session. You can increase your stretch in a variety of poses, improving elasticity and range of motion, according to the Bikram yoga website. These are incremental changes that should, with a regular practice over time, result in greater overall flexibility. One caveat: know your limits. That looser feeling can be deceptive. Increase stretches gradually to avoid injuring muscles by pushing too far too fast.

All yoga, including hot yoga systems such as hot vinyasa and the ashtanga and anusara sessions taught in heated rooms, uses your body weight to provide resistance. Because you work against gravity, yoga strengthens bones. In addition, the contraction and release of the poses stimulates and builds muscles. Hot yoga frequently calls for holding a pose, enhancing the value of a resistance workout.

You can sweat off a pound or two in a hot yoga class but that's just water weight. As soon as you replenish lost liquids, you reclaim every ounce. But the workout costs your body calories; a 150-pound person burns 715 calories for each 90-minute Bikram yoga session, according to Health Status calorie counter. Your mileage may vary, depending on your starting weight and how hard you work it, but do the math. Five classes or so could equal one lost pound. Don't slight hydration in order to feel even skinnier, though. Drink fluids before, during and after a hot yoga class to avoid a racing pulse, dizziness, nausea and other symptoms of heat exhaustion.

Hot yoga can be an effective aerobic workout. Heat intensifies the challenge to the heart and requires greater endurance, according to Diana Zotos, a yoga instructor and physical therapist in Manhattan's Hospital for Special Surgery. Bikram yoga's website details exactly how to calculate the aerobic value of your sessions to ensure you work within your target heart rate for optimal cardiovascular fitness.