Too Much of a Good Thing
Generally speaking, physical activity and exercise is recommended for better health. But it's more complicated than that. Can physical activity be excessive such that it is damaging rather than health promoting? Is there such a thing as too much physical activity?
For example, do joggers increase their risk of knee osteoarthritis? Are weekend warriors risking injury? A new study claims the answer is yes. Middle-aged men and women who participate in high levels of physical activity may be damaging their knees and increasing their risk of osteoarthritis.
Study Results Shed Light on Levels of Physical Activity
Study results were presented at the 2009 annual meeting of the Radiological Society of North America. The study involved 236 participants (136 women, 100 men, 45 to 55 years old, maintaining a healthy weight) who reportedly had no knee pain. The participants were divided into 3 groups based on their responses to a questionnaire about their type and level of activity.
MRI analysis revealed an association between physical activity level and severity of knee damage. Specifically, meniscal lesions, cartilage lesions, bone marrow edema, and ligament lesions were worse with high physical activity levels.
According to the study's lead author, this study and others suggest that high-impact, weight-bearing physical activity (running and jumping) is worse for knee health than low-impact activity (walking, swimming, and cycling) which actually may be beneficial. More research is needed for a definitive determination however.
Choose your activities wisely. For healthy, middle-aged people, low-impact physical activities may be best for knee health.
Too Much Physical Activity May Lead to Arthritis. RSNA.org. Accessed 12/1/2009.