Progression of therapeutic exercises and long-term benefits
When you are first given specific rehab exercises to do they have to be appropriate for what your body can handle at the time. Too difficult an exercise could easily make things worse or get you into bad habits. Sometimes to undo bad habits we have to start afresh with exercises which may seem very easy indeed.
Exercises which are very easy will only help you to a certain point. As you get better at doing them, or as they start to feel more comfortable, they can be changed in some way to make them slightly more demanding for the body. This way the body continues to adapt and become stronger, or more supple, or better co-ordinated and so forth. If exercises remain unchanged the body can lack sufficient stimulus to improve further. Therapeutic exercise progression is essential because it prevents you reaching an unnecessary limit too soon.
As your rehab exercise progresses it can seamlessly become more and more like 'fitness exercise' and ultimately athletic performance exercise if you go far enough. If you train, what you learn from your rehab can become integrated into your training. This helps improve your fitness or performance beyond where you were before your injury.
We should all regularly be doing some form of 'health and conditioning' exercise or 'body care' regardless of how fit we think we are. And when you let go of the idea of "rehab exercise" and see yourself instead on a seamless continuum of exercise that is appropriate for your current ability you continue regardless that your injury is better. Your exercises adapt with you.
With each injury you learn new things that you can progress and carry forward into your regular routines. This way, injuries and set-backs become a great opportunity for learning and gaining long-term benefits.