London, Nov 29 (IANS) Light exercise can prevent arthritis or delay its onset whereas strenuous activity may increase chances of its development.

A US team examined people at risk of osteoarthritis and questioned them about their exercise patterns.

‘Participating in a high-impact activity such as running for more than one hour a day at least three times a week appears associated with more degenerated cartilage and potentially a higher risk for development of osteoarthritis,’ says senior study author Thomas Link.

‘On the other hand, engaging in light exercise and refraining from frequent knee-bending activities may protect against the onset of the disease,’ adds Link, professor of radiology at the University of California in the US, reports the Telegraph.

The study involved 132 people at risk of knee arthritis but without current symptoms who were compared to 33 similar people at no increased risk.

MRI scans revealed that light exercisers had the healthiest knee cartilage among all exercise levels.

Moderate to strenuous exercise in women who did any amount of strength training was associated with higher water content and more degenerated collagen architecture in the knee.

The findings also showed that frequent knee-bending activities, such as climbing up at least 10 flights of stairs a day, lifting objects weighing more than 25 pounds, or squatting, kneeling or deep knee bending for at least 30 minutes a day, were associated with higher water content and cartilage abnormalities.

These findings were presented at the annual meeting of the Radiological Society of North America (RSNA).