Tai chi helps the waistline a little

Tai chi is the slow-motion exercise sometimes called "meditation in motion." Tai chi is popular for its dignified pace and low impact, but its claimed medical benefits have been difficult to pin down. In this assessor-blinded, three-way randomised trial, researchers compared regular tai chi practice, standard aerobic exercise, and usual care for reducing central obesity among adults older than 50.

The participants were mostly women, mean age was early 60s, mean body-mass index (BMI) was 25.6 kg/m2, and mean waist circumference was about 92 cm. About half of participants had dyslipidemia or hypertension.

After 38 weeks of thrice-weekly 1-hour tai chi or aerobic-exercise sessions, mean waist circumference in both groups had declined by 1 to 2 cm. In contrast, that measurement in a control group had increased by almost 3 cm. Mean values for weight, BMI, HDL cholesterol levels, and triglyceride levels were all slightly better in the tai chi group than in controls and were indistinguishable from those metrics in the aerobic-exercise group. At week 38, 10% to 15% of each exercise group no longer had formal diagnoses of central obesity, in contrast to 4% of the control group.

This rigorous study suggests that the modest metabolic benefits of regular tai chi practice approximate those of light aerobic exercise.