Should your joints fear exercise?

This week, an influential Pilates teacher trainer shared a video on her social media about how she had how she woke up in pain from her osteoarthritis that morning, but after Pilates was pain-free for the rest of the day. She eulogised (quite rightly) that motion is lotion and movement is medicine. 

However, she also said something that bothered me. When she was a teenager she was a competitive sprinter, and as an adult she taught aerobics for many years. This, she said, had led her to develop terrible osteoarthritis in her hips, knees and hands. She blames herself for her arthritis.

Arthritis* is the word used to describe joint pain and stiffness. Osteoarthritis is the most common form, and it can happen when the protective cartilage on the ends of your bones breaks down. Osteoarthritis is often colloquially known as, "wear and tear" arthritis, to distinguish it from other types; and it is tempting to believe that you can wear your joints out by subjecting them to impact. However, our bones aren't made of stone; they don't gradually erode. Instead, they are living organs that are continually being repaired and replenished.

That's not to say that joints are infinitely repairable. There are limits to how much damage a joint can experience without adverse effects in the long term. For example, osteoarthritis is far more common in retired football players than the general population, and people with a history of physically demanding jobs, especially involving kneeling, squatting, lifting and climbing also seem to suffer more. However, jobs that involved a lot of walking weren't found to have the same detrimental effect. As for recreational running, a systematic review of evidence from 2017 was unable to conclude whether running was beneficial, harmful or neutral with regard to knee osteoarthritis, and another from 2021 concluded that running helped to provide nutrition to knee cartilage. I was unable to find any research into the effect of aerobics on arthritis. However, a sedentary lifestyle is strongly associated with osteoarthritis

Certainly, as an aerobics teacher she will have put a lot of impact through her body (back in the day, aerobics teachers would have been giving 15-20 high-impact classes per week), and it is possible that this level of exposure to impact may have had an effect on her hips and knees. However, I can't see a way that aerobics or sprinting could have damaged the cartilage in her hands. There are other factors that are associated with osteoarthritis, such as age, family history, obesity and being female. Perhaps she would have succumbed to arthritis anyway?

What concerns me is that when influential people put out information saying that their aerobics caused their osteoarthritis, the teachers who follow them may start to advise against exercise involving impact. The risks of not doing aerobic exercise are very well established, not just to the risk of osteoarthritis, but also blood pressure, osteoporosis, heart problems, mental health....you name it!

So, don't fear exercise. Our joints have evolved to require some loading and impact to be healthy. If you have already developed osteoarthritis, please don't blame your history of recreational exercise. The chances are it helped to mitigate, rather than worsen it.

*The word is a combination of the prefix "arthro-", meaning "joint" (where we get the words "arthropod" and "articulated" from), and "itis," which means swelling.