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. Research needs and opportunities. Although many possibilities to further research can be considered, two areas are of primary importance - surgery and cancer. Yoga should be studied as a form of pain relief for surgical patients.