Is there such a thing a “too much exercise?”

With the increasing problems of obesity and cardiovascular diseases attributed to sedentary lifestyle, physical exercise has touted as the solution to lots of health problems. But can physical exercise also have some adverse effects on health? German and American researchers presented results at Radiological Society of North America (RSNA) in Chicago last year that indicated that high levels of physical activity can cause cartilage damage and lead to osteoarthritis.

According to Dr. Christoph Stehling, a researcher in the US and in Germany:

“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.”

Osteoarthritis is the most common form of arthritis, affecting about 27 million people in the US. It is a degenerative joint disease that causes pain, swelling and stiffness.

The researchers looked at 236 study participants (100 men and 136 women) with ages ranging from 45 to 55. The participants were asked to complete the Physical Activity Scale for the Elderly (PASE) questionnaire and based on their PASE scores, were classified as low, middle-, and high-activity groups. A person of high activity level would typically engage in several hours of walking, sports or other types of exercise per week, as well as yard work and other household chores. The participants were then subjected to magnetic resonance imaging (MRI) that looked at musculoskeletal structures of the knee.

The study results revealed the following knee abnromalities in some of the participants:

• meniscal lesions
• cartilage lesions
• bone marrow edema
• ligament lesions

The frequency and degree of knee damage seems to be associated with the level of physical activity based on PASE scores.

Dr. Stehling continues to say

“The prevalence of the knee abnormalities increased with the level of physical activity… In addition, cartilage defects diagnosed in active people were more severe.”

In addition, certain activities, especially weight bearing activities such as walking or running cause more damage than other activities. The researchers do not necessarily advocate a sedentary lifestyle, which can be also detrimental to musculoskeletal health. Instead, they recommend non-weight bearing activities such as swimming and cycling. These activities are beneficial to cardiovascular health without causing cartilage damage.

The study authors concluded:

•High levels of physical activity may result in knee damage and eventually arthritis for middle-aged men and women.

•MRI showed evidence of knee abnormalities, including cartilage damage and ligament lesions, in active adults with no pain or other symptoms