"The form is the alphabet; Pushing hands and San Shou are learning to read and write. The ability to read and write is what makes the alphabet useful." - Grandmaster Tchoung Ta-tchen
"T'ai Chi Ch'uan Lowers Blood Pressure"
Many students comment how the t'ai-chi they practice in our classes has helped them to keep their blood pressure under control. But, Dr. D. Young from Johns Hopkins University was surprised to find that t'ai-chi significantly reduced blood pressure. In a 12 week study, she found systolic blood pressure fell 8.4 mm Hg in the aerobic exercise group and 7mm Hg in the t'ai-chi group. The benefits were seen after only 6 week (AHA press release, Washington Post, 4/14/98, p. Z28). I don't find these results surprising, based on what students have said and the research we reviewed in past issues. Several studies showed that t'ai-chi ch'uan is an aerobic exercise and has reduced blood pressure. For example Dr. K. Channer found that t'ai-chi reduced blood pressure in cardiac patients (Postgrad Med J 1996 Ju;(848):349-351) and Kurland (UW 1975) found it lowered blood pressure acutely after one session in normal, non-hypertensive, students.
Aerobically, the t'ai-chi ch'uan slow form was found by Kurland to be 3 to 4 METS* (Sports Med., Training and Rehab., 1992, Vol 3, p228). Dr. D. Zhou, et al., found the t'ai-chi long form to be 4 METS, (Can J. Appl Sport Sci 1984, Mar;9(1):7-10). Zhou classified the Yang style "long form" as a moderate form of aerobic exercise.
*one MET(metabolic unit) is equivalent to resting metabolism, about 3.5 m; O2/kg/min. 3 METS is equivalent to walking at 3 MPH.
Dr. Ching Lan of the National Taiwan University Hospital found that there was a significant increase in aerobic capacity (VO2max) from practicing t'ai chi ch'uan. He found a 16% increase in aerobic capacity in men and 20% increase in women. Dr. Lan found a significant increase in flexibility and knee strength as well. The exercisers averaged working out 4.6 days a week for 11.2 months. Classes consisted of 20 minute warm-ups, 24 minutes of t'ai-chi and a 10 minute cool down. (Medicine & Science In Sports & Exercise, 1998) Dr. Lan also found that classical Yang and Chen styles were 4-5 METs for women and 5-6 METs for men. This is a higher energy expenditure than found by Kurland or Zhou. Dr. Lan also found differences between several versions of Yang style, some with higher energy expenditures and others lower. The percentage of knee bend while doing the tai chi form changes the energy expenditure. More on aerobic and orthopedic benefits next issue.