Watching a group of people doing tai chi, an exercise often called “meditation in motion,” it may be hard to imagine that its slow, gentle, choreographed movements could actually make people stronger. Not only stronger mentally but stronger physically and healthier as well.

I certainly was surprised by its effects on strength, but good research — and there’s been a fair amount of it by now — doesn’t lie. If you’re not ready or not able to tackle strength-training with weights, resistance bands or machines, tai chi may just be the activity that can help to increase your stamina and diminish your risk of injury that accompanies weak muscles and bones.

Don’t get scared by its frequent description as an “ancient martial art.” Tai chi (and a related exercise called Qigong) does not resemble the strenuous, gravity-defying karate moves you may have seen in Jackie Chan films. Tai chi moves can be easily learned and executed by people of all ages and states of health, even those in their 90s, in wheelchairs or bedridden.

It’s been eight years since I last summarized the known benefits of this time-honored form of exercise, and it has since grown in popularity in venues like Y’s, health clubs and community and senior centers. By now it is likely that millions more people have become good candidates for the help tai chi can provide to their well-being.