Over-Exercising Could Lead to Osteoarthritis

A new study finds that middle−aged people who are very active may unwittingly do damage to their knees and put themselves at increased risk for developing osteoarthritis. The degenerative disease is the most common form of arthritis and is caused by accumulating stress to the joints.

The study, presented at the Radiological Society of America’s annual conference, followed 236 people between the ages of 45 and 55, who were all in good health at the study’s outset, and reported no symptoms of osteoarthritis. Based on their answers to questions about their activity levels, participants were categorized as being low−, middle−, or high−activity. Those in the high−activity group spent at least a few hours a week exercising, and also engaged in other physical activities like yard work and gardening.

Since exercise is generally greatly encouraged by health professionals, and known to ward of a litany of age−related health concerns, what is one to do? Sticking with low−impact activities may be the answer.

The researchers used MRI scans to determine the condition of the participants’ knees. They looked for damage that included edema (fluid build−up) in the bone marrow as well as lesions to the cartilage, ligaments, and menisci (cartilaginous structures that help absorb tension). They found that, as suspected, the more people exercised, the more damage they had in these parts of the knee.

“The prevalence of the knee abnormalities increased with the level of physical activity," said study author Christoph Stehling, a research fellow at the University of California, San Francisco. "In addition, cartilage defects diagnosed in active people were more severe.” He adds that the findings suggest that people who are more active may actually be putting themselves at greater risk for developing osteoarthritis than those who are less active.

Since exercise is generally greatly encouraged by health professionals, and known to ward of a litany of age−related health concerns, what is one to do? Sticking with low−impact activities may be the answer. “This study and previous studies by our group suggest that high−impact, weight−bearing physical activity, such as running and jumping, may be worse for cartilage health," said Stehling. "Conversely, low−impact activities, such as swimming and cycling, may protect diseased cartilage and prevent healthy cartilage from developing disease.”