It shouldn't be too much, just no joint-intensive disciplines such as tennis, squash, jogging or aerobics. At least that's what it says. Because inactivity is far worse for the knee. Is that correct? For ten years, a team from Northwestern University in Chicago studied the risk of gonarthrosis, painful and inflammatory wear and tear on the knee joints, of almost 1200 men and women. The average age of the subjects at the start of the study was 58 years, and their average body weight was slightly above the norm. Some of them complained of occasional knee pain, but their medical findings were still normal in this joint. So you belonged to the risk group for osteoarthritis of the knee, but had not yet specifically developed it.