Unlike many exercise programs, Yoga practice does not take energy away from the system; instead, it puts energy back into the system. Contrary to most exercise programs that leave you exhausted, your Yoga exercise period will leave you refreshed and renewed. When Yoga exercises are combined with breathing and meditation techniques, the Chronic Fatigue Syndrome patient has a daily support system that makes a productive life possible.
Here's how it works:
Physical and emotional tension and fatigue lodge in muscle tissue, making it knotted, hot, and the circulation sluggish. Yoga exercises systematically stretch and relax the major muscle groups and push fresh blood/oxygen through the tissues, which releases the tension and allows the muscles to relax and cool. The exercises are done slowly, and the breathing patterns with each exercise allow for maximum oxygen intake and for the release of toxins.
Poor circulation also means the brain and other vital organs get less blood and important nutrients. Yoga exercises improve all-over circulation by limbering the spine, by movements which improve elasticity in the blood vessels, and by selected inverted poses, which use compression to pump more oxygen throughout the body.
Breathing techniques improve concentration and awareness, and help to reduce stress reactions. Extreme reactions to stress – especially when they are triggered by a past event or a future fear, or by a situation that cannot be changed – cause energy demands to increase rapidly. Your breathing techniques put you in touch with an unlimited source of energy that lies within you. By constantly returning the mind to the present moment, you allow the body to deal with what's happening now.
Relaxation and meditation teach conservation of energy and build self-confidence. The student learns to completely relax every muscle in the body and then to forget about the body while turning attention toward the mind in meditation. In meditation you simply stop all thought momentarily, allowing the strength within you to express itself.
Source: American Yoga Association