New research suggest, it may not be wise for middle-aged men and women to overdo their exercise regime, as they risk arthritis by doing so.

The American study on over 200-normal weight participants aged 45 to 55 found, the ones who exercised excessively seemed the most likely to suffer from damaged knees, as running and jumping caused more damage to cartilage and ligaments than swimming and cycling.

However, one of the arthritis charities claims, it was far more important to keep fit and was certain most people would not experience any exercise related problems.

Osteoarthritis affecting 8-million people in the UK is the commonest form of arthritis, a degenerative disease of the joints causing pain, swelling and stiffness in them, more common in women than in men, a risk that increases as we age and gain weight.

The survey questionnaire designed for figuring out how much exercise the study participants did, split them into low, middle and high-activity groups.

The high-activity individuals indulged in several hours of walking, sports or other types of exercise each week, including doing their own gardening and other household chores.

After, MRI scans of the knee were done to find any tears, lesions or other abnormalities in the cartilage and ligaments, with any damage seen associated solely to activity levels and not age or gender.

Dr. Christoph Stehling, who lead the study says, the study data found people with higher physical activity levels were at greater risk for developing knee abnormalities i. e. at a higher risk of developing osteoarthritis. The study as previous studies, also found high impact, weight-bearing physical activity like running and jumping worsened cartilage health, while low-impact activities like swimming and cycling protected diseased cartilage and prevented healthy cartilage from getting diseased.

Even so, a spokeswoman for the Arthritis Research Campaign said gains of exercise far outweighed potential risks.