During the past 80 years, health professionals in India and the West have begun to investigate the therapeutic potential of yoga. As the practice of yoga has gradually moved into the West, it has been used most often as part of an integral program of health enhancement as well as for the treatment of chronic diseases. Studies of meditation were discussed previously in this section. Here, the focus is on the therapeutic utility of programs that combine hatha yoga and prahayama yoga. A typical yoga session as practiced in the United States lasts 20 minutes to an hour.
Some people practice daily at home, while others practice one to three times a week in a class.
A session usually begins with gentle postures to relax tension in the muscles and joints, then moves to more difficult postures. Every movement should be made gently and slowly, and practitioners are urged not to stretch beyond what is comfortable for them. Emphasis is placed on breathing slowly from deep in the abdomen. Specific pranayama breathing exercises also are an important part of the practice. Since it began in the 1920s, scientific research on yoga has been enormous.