Do you know of any runners who can't run anymore?

Well...I was TOUGH ****..But now I'm not...although I need to experiment but I'm 99.99999999999% sure I don't have the ability to do it because my brain lost the logical critical thinking ability to understand how to hold in the pain to run 6 miles per hour for 30 minutes like I used to. Right now all I know is that at the moment currently 6 miles per hour for 15 minutes is easy as ****. Yah I'm still tough ****.

Oscar Pistorius

Yes. I know some who have stopped running due to injury or disease. Some of my friends who used to be runners are now walkers/woggers.  I've had to drop to running less due to knee issues, but I walk/wog. 

Yes, at my age I do know some people who used to be runners who can't do that anymore.

Yes. One had a joint replacement. He was advised running would cause the artificial joint to fail.

Lots, myself included. No matter how healthy and active you are, time has a way of dealing blows to various joints.

I might be able to run if my life depended on it, but the pain from my knees would have me in tears. Arthritis, such fun.

me honestly I used to run from my bed to the kitchen, but honestly I can't run anymore so now I just speed walk.