Certain Tai Chi movements or Qi gongs can be used to change the bodies state to heal it. For example if the body is too yin. Examples of being too yin would be, not wanting to engage in anything, being very quiet, being very closed off to others. Examples of being too yang would be, being too loud, getting into fights all the time, being very open with emotion, be it angry, upset, even happy. Keep in mind these states could also be caused by factors other than being too yang or too yin.
But if you take a Qigong or Tai Chi form, combined with a change of diet you can change the state of the body for the better. Even if the state is not cause by the condition of being too yang or yin, you can still try out the Qigong or Tai Chi and see if it helps. If it helps then it’s probably that the state of body was caused by being either too yin or too yang, and if it doesn’t work then no harm will have been done, in most cases though even if the state is not caused by being too yang or too yin, the Tai Chi or Qigong will have helped greatly simply because it helps to balance the body out no matter what the condition.