Running could, contrary to popular belief, be good for the knees. A new study at Brigham Young University in Utah found that running alters the biochemical environment of the knee in a way that keeps it lubricated and less susceptible to inflammation.
Researchers examined the blood of six runners under the age of 30 with no history of knee injury or arthritis. They also extracted a small amount of synovial fluid, a lubricating fluid that reduces friction inside joints, from the right knee.
The volunteers were taken, in wheelchairs, to the university’s biomechanics lab on two different days. On one day they sat quietly for 30 minutes and on another they ran on a treadmill for 30 minutes. Then samples of blood and synovial fluid were taken.
The researchers looked for two things in the samples: molecules associated with inflammation and cartilage oligomeric matrix protein (COMP), a substance that accumulates in arthritic knees.
In almost every case the runners had lower levels of two types of cells that can contribute to inflammation in the synovial fluid. There were also lower COMP levels in the synovial fluid, but higher levels in the blood, suggesting the molecules had been pushed out of the knee into the blood.
The findings suggest that half an hour of running changes the interior of the knee, reducing inflammation along with a marker of arthritis. The study was published in the European Journal of Applied Physiology.
Previous studies have shown that long-term runners are less likely to develop osteoarthritis in the knees than non-runners, but did not establish causation.
Robert Hyldahl, the study’s lead author, said the findings suggested moderate amounts of running were ‘not likely to harm healthy knees and probably offer protection’ against joint damage.
This is an interesting study, as the suggestions go against what most people believe to be true about running: that it can cause damage to the knee joints due to its high impact nature. Unfortunately this study alone doesn’t provide us with enough evidence to change our minds just yet.
Firstly, it is based on only six results, an extremely small study size. Second, the study was based on very short term information, and even then it did not measure knee damage or osteoarthritis.
What is more, running was compared against sitting. What would be really interesting here would be to compare it with other forms of exercise, as well as using larger numbers of people and measuring longer term data.
Research score: 2/5