Despite the beneficial effects of physical activity in keeping individuals healthy, a new study finds excessive exercise in the middle-aged population may lead to arthritis.

According to the study presented at the annual meeting of the Radiological Society of North America, osteoarthritis particularly of the knee is more common in middle-aged individuals over-exercising.

While previous studies had reported a higher risk of osteoarthritis in older and heavier women, this study suggested that the severity of the damage solely depended on the activity levels and the type of exercise a person did.

"Our data suggest that people with higher physical activity levels may be at greater risk for developing knee abnormalities and, thus, at higher risk for developing osteoarthritis," said lead researcher Christoph Stehling.

Compared to swimming and cycling the study found that weight-bearing physical activities such as running and jumping are more harmful for cartilage and ligaments.

Scientists therefore urged individuals particularly those with a history of joint or ligament injury to be cautious about weight-bearing exercise, adding that swimming and cycling are better options for this group.

"Many people wrongly assume that exercising when you already have arthritis is a no no, but in fact appropriate exercise is one of the best ways to help control pain, boost energy, keep you mobile and strengthen your joints," they added.

PKH/HGH