Previous research has found conflicting results on a link between exercise and knee arthritis, but now it seems that the amount of physical activity you do has no impact – though more strenuous workouts might
3 November 2021
There seems to be no link between the amount of exercise people do and whether they develop painful osteoarthritis in their knees, according to a large study of activity levels and arthritis pain. But the research couldn’t rule out that high-impact forms of exercise like running bring on the condition.
Osteoarthritis is more common as people get older and is sometimes referred to as a “wear and tear” condition. Arthritic knees often have visible damage to their cartilage, a rubbery layer that covers the ends of bones.
Previous studies have found conflicting results on whether exercise can make arthritis more likely. So Lucy Gates at the University of Southampton in the UK and her colleagues combined the results of six such investigations, involving over 5000 people who initially had no knee pain or other evidence of arthritis.
At the outset, people were asked about how much exercise they did, including playing sports, walking and cycling. They recorded the average time spent exercising each week, and their activities were graded by their metabolic equivalent, or MET, scores, a standard way of classifying activities according to how much they raise a person’s metabolic rate.
At the end of the studies, which lasted from five to 12 years, people were also asked if they had developed frequent knee pain or if arthritis had been diagnosed by a scan.
The likelihood of developing arthritis didn’t correlate with activity levels, either by how much time people spent exercising each week or by their combined time and MET scores.
“There’s more work to be done on disaggregating risk and different types of activity,” says Gates. “The next step is to figure out how different weight-bearing [activities] might change things.”
“We are not at the stage to say there’s no relationship there,” says team member Thomas Perry at the University of Oxford.
Journal reference: Arthritis & Rheumatology, DOI: 10.1002/art.42001
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