Knee problems occur with too little or too much exercise says new research.
Doctors at the University of California, San Francisco found that high and low levels of physical activity can speed up the damage to knee cartilage in middle-aged people.
The study looked at 205 patients between the ages of 45 and 60 years-old that were part of the Osteoarthritis Initiative, a massive study on knee osteoarthritis.
MedPage Today said that researchers looked at cartilage degeneration in those participants over a four-year period.
They use MRI screenings to measure the evolution of the deterioration.
PhysBizTech reported that the researchers found that those who participated often in high-impact activities such as jogging were at a higher risk for osteoarthritis in the knees.
They found the same for those who did no activity at all.
The research suggests that moderate activity is the way to save the knees from osteoarthritis.
"This study seems to suggest that people should do things in moderation," said study author Wilson Lin during a press briefing, reported MedPage Today.
"You want to exercise the knee, but you don't want to stress the knee in such a way that would be detrimental. If [people] wanted to run marathons and work out several times a week, I would present them with the evidence that this could be harmful."
The study was presented to the meeting of the Radiological Society in North America (RSNA).