Answer:
When you push your body upwards or change your body's position in calisthenics you are doing isotonic exercises. On the other hand, When you are holding a pose in calisthenics, you are doing isometric exercises.
Explanation:
In Isometric exercises, the muscles contract, but they keep their tension and the length of the muscles is hardly affected. when you are holding a pose in calisthenics, you are doing an isometric exercise. In other words, there is no movement of the body, but there is a contraction of muscles to maintain the pose.
Isotonic exercises produce the contraction of a muscle when this is used to lift something, as a result, the muscle becomes shorter during contraction. In calisthenics, an isotonic exercise would be lifting your body weight to do a pose.