"Clearly, in future studies we need a true 'no exercise' control group," says Young. "This study was a pilot, and more research is needed."

Extensive evidence indicates that regular aerobic exercise can decrease resting blood pressure by approximately 10 millimeters mercury, and that mild exercise may reduce blood pressure just as much or even more than strenuous activities, such as jogging. Mind-body exercises such as tai chi may provide an added boost to both physical and mental health, which is why the Eastern healing art is increasingly being studied by Western medical practioners.

A growing body of research suggests that practicing tai chi has many benefits for seniors, including a reduced risk of falling and a significant improvement in quality of life. Tai chi is now being used in some cardiac rehabilitation programs and by people with diseases such as fibromyalgia, arthritis and multiple sclerosis, notes Harvey Kurland, an exercise physiologist from San Bernadino, California, who has been studying and teaching tai chi for nearly 30 years. His research, published in the journal Sports Medicine, Training and Rehabilitation, found tai chi to be a low-intensity aerobic exercise equivalent to walking at a three-mile-per-hour pace.

"In Chinese medicine, tai chi is used as a way to relax the body and let the chi (vital energy) flow throughout the body," says Kurland, who credits the 1993 PBS-TV series "Healing and the Mind" with sparking an explosion of American interest in tai chi. Physical activity is considered an essential component to health by the Chinese, who believe that without daily movement the body's "chi" can become stagnant and lead to illness. The existence of this life force has never been scientifically proven by Western standards.