It is necessary to keep the body fit and healthy. There is nothing inherently wrong with calisthenics, exercise, fitness training, etc. Yet like anything else in life, people of this era take things too far. It is up to you to determine how to balance your activities and know when an action is in harmony or when it is motivated by desires, defects, etc.

For instance, one has to measure the ultimate result of our pursuits: time and energy invested into physicality will have a very limited benefit because the body itself is impermanent and unreliable and we will lose it inevitably, meaning whatever we invest into it will be lost. Yet time and energy dedicated to developing consciousness, especially through meditation, has no such limitation, because the consciousness is eternal: whatever we invest into it will not be lost.