I started Bikram Yoga 1 1/2 years ago when I started to get better and had enough energy to exercise. I thought it would be stretching in a heated room (my Dr. encouraged me to take saunas) but found it very taxing. It's a 90 minute active form of meditation and concentration to reconnect your mind/body, combined with a series of 27 breathing, standing, sitting, kneeling, lying down poses separated by sit ups and rests. The room is kept around 105 degrees F/40% humidity to promote deep stretching of muscles, but also causes you to sweat and detoxify. I lose about 2 pounds of sweat each class, but get it back by drinking water. The various poses are meant to tone muscles and strengthen the immune system among many other benefits. At first the hardest part was breathing correctly, like I was suffocating for oxygen. Maybe this is cytopathic hypoxia linked to ATP? (http://www.mitochondrial.net/showabstract.php?pmid=9248546) After going at least 3 times a week, it has gotten easier and I even have days were I am able to breath normally. Now these classes are my litmus test to measure where my health is, and don't consider myself sick anymore. Has any one else tried this and had any success?