If you are worried that you will cause damage to your doorway or to your walls there are small tricks you can do in order to avoid this. However, this doesn’t happen frequently. In fact, in order for it to happen, you have to have extremely thin walls and door frame that has visibly low quality. In this case, there is nothing you can do. However, for most of you, there is a solution to your problem.
The trick with the leverage pull up bar is to relieve the pressure on the pressure points somehow. The two pressure points are the one on the top of the bar that comes in contact with your door trim and the one on the other side of the door that holds the bar in place. If you put a small piece of wood in both pressure points you will manage to avoid the damage to your doorway by lowering the pressure. The pressure is lowered because by placing a piece of wood between the bar and the door frame, it reliefs the pressure by absorbing part of it and by changing the whole structure by a couple of millimeters.
In telescopic pull-up bars, however, decreasing the damage to your home is not possible. The good news is that there is not much damage done with this type of a pull-up bar. If you decide to lower the pressure on the sides, you will be lowering the quality of the entire structure; therefore it will not be stable anymore. And if you decide to use caps, the two holes on each side of the doorway will remain there even after you decide that you are not going to use it for a while.