Q. You've listed tai chi among the least beneficial activities for bone mineral density. But I've read it can help keep bones strong. What's the deal?
A. It’s hard to say, but if there is a benefit, it is probably limited. Most studies on the subject have been small, and the results inconsistent, probably because tai chi can vary so much.
One of the better studies, from Hong Kong in 2004, involved 132 women in their fifties, half of whom did supervised tai chi (45 minutes, 5 times a week) for a year; the other half did no exercise. Bone loss in key areas, such as the lumbar spine and proximal femur (upper thigh bone), was not significantly reduced in the tai chi group. In contrast, a study from Texas Tech University in 2007 found that 14 people (average age 79) who did tai chi for 40 minutes 3 times a week for 6 months had modest improvements in markers for bone formation.
Research reviews also differ. A 2008 review in Osteoporosis International concluded that the evidence about tai chi and bone health is “not convincing.” In contrast, a 2011 review in Alternative Medicine Studies said that in studies of postmenopausal women, tai chi seems to reduce bone loss.
Tai chi is weight-bearing—involving slowly shifting your body weight from leg to leg—and this may stimulate bone formation somewhat. As we discussed in the past, the best activities for maintaining bone mineral density are those that are high in impact, such as running, tennis or jumping rope, as well as resistance workouts, such as weight-training.
Bottom line: Tai chi has lots of potential benefits that are well-proven. Even if its direct effects on bone strength and quality are limited, it can still help prevent fractures because it improves balance, neuromuscular coordination and postural stability, thus reducing the risk of falls.