Save the knees
Right up there with “Run, Forrest, run!” among the things runners love to hear is, “Aren’t you worried you’re going to wear your knees out?” In truth, the evidence from numerous studies over many decades strongly suggests that regular runners are less likely to develop osteoarthritis in their knees than nonrunners – a finding that still raises skeptical eyebrows. How is it possible that running doesn’t ruin your knees?
One obvious contributor is that running keeps your weight lower, which reduces the load carried by your joints. It’s also a non-contact activity where acute knee injuries like acl tears, which really do raise the risk of subsequent osteoarthritis, are rare. But a third, more subtle possibility is that aerobic exercise has anti-inf lammatory effects throughout the body, including in the joints, which slows the progression of conditions like osteoarthritis.
That’s the theory that researchers at Brigham Young University tested in a recent study in the European Journal of Applied Physiology. They tried to extract synovial f luid, which is the joint’s lubricant, from the knees of healthy runners before and after a 30-minute run. The problem is that healthy knees have very little synovial f luid, so the researchers were only able to get enough pre- and post-run f luid from six of their 15 subjects. That means the results don’t really tell us much, though there were some promising hints that markers of inf lammation and cartilage turnover may have been affected by the run. For now, file this under “interesting but unconfirmed ideas” – and keep running.