Most of your training is concerned with developing a certain way of moving.
This kind of motion is called 'internal'.
Various drills have been designed as a means of experimenting with how you use the body.
It takes time for your muscles and nerves to re-grow but they will.
Once you have gained a new body skill, it will remain.
We regard the body as a conduit through which energy and motion can be transmitted.
Until your body changes and becomes loose, it will block the flow of energy.
Fa jing will not pass through a stiff body.