CARDIOVASCUALAR BENEFIT. Research has shown that the extremely gentle low impact T'ai Chi exercise can provide the same cardiovascular benefit as moderate impact aerobic exercise. The Harvard Women's Health Watch reported, "studies support Tai Chi [use] for heart-attack and cardiac-bypass patients, to improve cardiorespiratory function and reduce blood pressure."

A total of 29 studies met inclusion criteria, including 9 randomized controlled trials, 14 nonrandomized studies, and 6 observational trials. The study subjects included patients with coronary heart disease, heart failure, CVD, and CVDRF (hypertension, dyslipidemia, impaired glucose metabolism). Tai Chi interventions ranged from 8 weeks to 3 years, and the sample size ranged from 5 to 207. Most studies reported improvement with Tai Chi intervention, such as reduction in blood pressure and increase in exercise capacity. In addition, no adverse effects were reported. The authors concluded that Tai Chi may be a beneficial adjunctive therapy for patients with CVD and CVDRF.- Medscape Today, from WebMD, 10/26/2010
Read entire article at: http://www.medscape.com/viewarticle/729132

The Tai Chi group showed 19% higher peak oxygen uptake in comparison with their sedentary counterparts. In addition, the Tai Chi practitioners had greater flexibility and lower percentage of body fat in comparison with their sedentary counterparts.
-- Archives of Physical Medicine & Rehabilitation 77(6), 612-616
  Tai Chi was observed to be equally effective as aerobic exercise in reducing both systolic and diastolic blood pressure.
A growing body of evidence suggests Tai Chi practice, even over short periods of time, may improve cardiovascular health. Depending on how it is practiced, Tai Chi has been characterized as a low to moderate intensity exercise. Three studies are briefly discussed to illustrate the types of evidence available to evaluate the impact that Tai Chi may have on components of cardiovascular health. Young et al. [4] conducted a well designed, randomized controlled trial with 62 subjects that compared the effects of aerobic exercise versus Tai Chi on blood pressure in mildly hypertensive older adults. Over the 12-week study period, Tai Chi was observed to be equally effective as aerobic exercise in reducing both systolic and diastolic blood pressure.