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Undue high-impact exercise ups arthritis risk

November 30, 2009 12:00:00 AM PST
A study of more than 200 people, ages 45 to 55 found those doing the most exercise were the most likely to suffer knee damage.Certain high-impact exercise including running and jumping may also do more damage to cartilage and ligaments than swimming and cycling, say researchers at U.C. San Francisco.

However, experts say it is important for people to keep fit and the benefits from exercise outweigh the potential risks.

Osteoarthritis, a degenerative joint disease, is most common in women and risks increase with age and weight gain.

In the study, a typical high-activity person exercises several hours per week, including gardening and other chores.