Sometimes my knees hurt.

I have been doing spinning exercise for 7 years. Usually, I am fine, but on days when I think I overexerted myself, my knees always hurt. Fortunately, the hospital said there is nothing wrong and did not tell me to rest from exercise.

I tried swimming again for a while, thinking about my body, but as expected, spinning is the most enjoyable, so I can't give it up. I have to ride gently to avoid knee pain, but once I get caught up in the excitement, I can't control this body. What should I do?