And some people running is generally heel first landing, the impact is even greater.
Dancing has a lower impact and frequency on the knee, and it is usually a toe-first landing, which is just the right amount of cushioning.
If you have an old knee injury, try to minimize running.
If your knee is not injured, and you are willing to run, run, after all, running is the king of sports, the exercise of the heart and lungs is other sports can not be replaced.