The 105-degree Fahrenheit heat of a typical Bikram hot yoga class facilitates stretching and induces an elevated heart rate as your body circulates extra blood to the skin's surface to keep itself cool. Founder Bikram Choudhury said that the heat component mimics the climate of his native India and helps detoxify yogis' bodies through sweat. The way you practice, among other factors, determines how high your heart rate goes during the 90-minute sequence.
Bikram yogis perform Choudhury's copyrighted 26-posture beginner series using the same sequence every time. Theory holds that each posture builds on the one that preceded it and prepares your body for the next one in an orderly, scientific manner. Research published in the Journal of Exercise Physiology, by scientists at Texas State University, finds that students in a Bikram yoga session raise their heart rates to a peak of 133 to 175 beats per minute. In addition, this research suggests that regardless of how experienced you are at Bikram yoga or the number of times a week you practice, you may experience a lower resting heart rate and blood pressure over time.
The postures of the standing series, which constitute roughly the first half of class, make the most demands on your cardiovascular system and are designed to elevate the heart rate for maximum internal heat. Bikram yogis try to hold balancing postures such as Standing Head to Knee Pose and Standing Bow Pulling Pose, for example, for an initial set lasting 60 seconds and a second set that lasts 30 seconds. Your heart rate further increases through Balancing Stick pose until it peaks in Triangle Pose, which Bikram theory considers the "summit" of the standing postures. The second half of class consists of postures you perform while either lying or sitting on the floor. The floor postures are intended to focus less on heart rate and more on deep, internal work.
Target Heart Rate
By working hard in the postures, you can increase your heart rate for greater potential fat burn or cardiovascular conditioning. Strive to hold the postures until the teacher releases you, and focus on full contraction of the relevant muscles, particularly in balancing postures that require a locked knee. Your maximum heart rate is 220 minus your age for men; 226 minus your age for women. Working at 60 percent to 70 percent of that number will enable you to burn fat, and 70 percent to 80 percent gets you to cardio territory.
There is no prohibition against bringing a heart monitor to a Bikram yoga class, and some students have been known to do so, particularly pregnant women. In his book "Bikram's Beginning Yoga Class," Choudhury recommends that people with heart health or high blood pressure issues practice Bikram yoga only with a doctor's approval. He also advises such patients to hold each posture for only five counts at a time, resting and repeating as necessary for the recommended duration of the pose. If these considerations apply to you, let your Bikram instructor know prior to class. As with any exercise, stop practicing and check with your doctor if you experience chest discomfort, nausea, pronounced dizziness or related symptoms.