Here is the thing: there are many of us who love running and many others who are simply addicted.
Among both groups, many runners older than 50 years of age have knee osteoarthritis, and they run happily!
When my patients ask me if they can keep on running despite their osteoarthritis (OA), my answer is YES if you enjoy it!
I have recently led a training for physiotherapists about Running and the guidance on the topic is:
"runners with knee OA, whose exercise session may be shorter and at a lower intensity, should not be discouraged from doing it!"
The reason is this specific group of runners, running is related with improved knee pain.
Surprised? Below are some possible reasons:
a) running increases muscle strength and this may be responsible for decreasing the impact felt by the knee
b) muscle stimulation resulting from running may be responsible for the pain reduction
c) runners may have better proprioreception that helps mitigate the stress occurring within a knee involved in running.