Your Knee Has Arthritis. Should You Protect It, or Use It More?
If an X-ray shows arthritis in your knee, being told to exercise can sound contradictory.
If the joint is already worn, shouldn’t I protect it? Won’t walking more wear it out faster?
It’s an understandable concern. But our understanding of knee osteoarthritis has changed considerably.
For many people, the answer isn’t to use the knee less.
It’s to help the knee become better at handling movement.
What does the research tell us?
A large 2025 systematic review and network meta-analysis published in The BMJ examined 217 randomized controlled trials involving 15,684 people with knee osteoarthritis.
Exercise improved pain, physical function, walking ability, and quality of life. Aerobic exercise, such as walking, cycling, and swimming, performed particularly well across several of these outcomes.
Strengthening and mixed exercise programs were also beneficial, particularly for improving function.
That matters because treatment for knee arthritis does not necessarily have to be complicated.
Sometimes walking really is part of the treatment.
What about “wear and tear”?
This is where the language around arthritis can create unnecessary fear.
Terms such as degeneration, wear and tear, or bone-on-bone can make the knee sound like a mechanical part with a limited number of movements left.
But a joint is living tissue.
Your ability to walk, climb stairs, exercise, or get out of a chair depends on much more than what appears on an X-ray. Strength, mobility, balance, cardiovascular fitness, and your body’s tolerance to load all matter, and many of these can improve.
An arthritic knee does not automatically mean an incapable knee.
Can exercise actually help the cartilage?
This is where the science gets especially interesting.
Cartilage responds to its mechanical environment. Experimental and animal research suggests that appropriately dosed loading can influence cartilage biology and, under certain conditions, promote adaptive or reparative responses.
But we need to be careful with that finding.
We cannot currently say that exercise regrows cartilage in people with osteoarthritis.
What we can say is reassuring: a systematic review of randomized human trials using MRI found that therapeutic knee-loading exercise generally did not appear to damage articular cartilage. Some studies even found favourable changes in cartilage composition, although the overall quality of this evidence was low.
So instead of thinking:
“Every step is wearing my knee away,”
a more accurate way to think about it may be:
“My joint responds to load, and the amount and type of load matter.”
But what if exercise hurts?
Exercise for arthritis does not mean ignoring pain and pushing through everything.
It also doesn’t mean stopping whenever you feel discomfort.
Someone who becomes significantly more painful after a 30-minute walk may begin with 10 minutes. Someone who struggles with walking may initially tolerate cycling, pool exercise, or strengthening better.
The question isn’t only:
“Does it hurt?”
It’s also:
“How does my knee respond to this amount of activity?”
The goal is to find a manageable starting point and progressively build from there.
Build capacity, not fear
When a painful knee leads someone to move less, the leg can become weaker, fitness declines, stairs become harder, and eventually even ordinary activities require more effort.
Rehabilitation tries to reverse that cycle.
Move.
Build strength.
Increase walking tolerance.
Recover.
Then gradually do more.
There is no single perfect exercise for every arthritic knee. The right program depends on your symptoms, abilities, goals, and what you can realistically continue doing.
The goal is not to protect your knee from movement for the rest of your life.
The goal is to build a knee, and a body, that can handle more of it.
Sometimes your knee needs rest. Sometimes it needs treatment.
But very often, it also needs something remarkably ordinary:
It needs to be used.
References
Bricca, A., Juhl, C. B., Steultjens, M., Wirth, W., & Roos, E. M. (2019). Impact of exercise on articular cartilage in people at risk of, or with established, knee osteoarthritis: A systematic review of randomised controlled trials. British Journal of Sports Medicine, 53(15), 940–947.
Yan, L., Li, D., Xing, D., et al. (2025). Comparative efficacy and safety of exercise modalities in knee osteoarthritis: Systematic review and network meta-analysis. BMJ, 391, e085242.
