Comment by adrian_b

It is not so simple.

Tai Chi, like many other exercises that have been derived from former martial arts, is a complete exercise, for all muscles and articulations, especially when one of the older long forms is practiced, not one of the modern compressed forms.

There are a lot of examples of sports or gym practices that are not very good as a health-preserving exercise if they are the only exercise that is done.

Tai Chi is among the exercises that can be sufficient even if it is the only exercise that is done.

It is not difficult to compose a routine that exercises all the parts of the body, but those are usually more boring than exercises like the Tai Chi forms.