I think I'm getting old...

Last week at tennis I turned my ankle while going for the ball and my leg crumpled underneath of me. While I was in some pain, I was still able to finish my lesson with no problem but ever since then I've been dealing with knee and hip problems related to the fall. So I have to ask myself, "Am I just getting old?" Ten years ago, I would've walked it off and it would never have been a problem. It is a sad realization to know that you aren't recovering as quickly as you used to. So, right now I'm trying to decide if I should see the doctor or not. I'm continuing to exercise but I fear that I may be making things worse. Yep, I'm definitely getting old...