This just in

A German medical team gave 22 midpack runners (yep, that's where I fall) a knee MRI before and immediately after they completed a marathon. The researchers concluded that "marathon running does not cause severe, acute lesions of cartilage, ligaments, or bone marrow of the knee in well-trained runners." Source: European Radiology.

Bottom Line: No harm done; marathon running doesn't hurt the knees.

So, I can now spout medical findings, courtesy of those German doctors, to combat all those well-meaning friends who have concern for my knees in my later years. No need to worry.