Osteoarthritis: How Exercise, Strength and Weight Management Can Help

You've been told your joint is "worn down." Maybe the words "bone on bone" appeared in a scan report, or a clinician suggested you avoid certain activities to protect what cartilage you have left. If that's your experience, the most important thing we can tell you is this: that framing is outdated, and it may be doing you more harm than the condition itself. Osteoarthritis is the most common joint condition in the world, affecting around 528 million people worldwide in 2019. It is a major cause of pain and disability worldwide, particularly among older adults. And yet it remains one of the most widely misunderstood conditions, because the story patients are most often told does not match what the evidence actually shows.

What Osteoarthritis Actually Is

Osteoarthritis (OA) is a disease of the whole joint, not just the cartilage. It involves changes to the cartilage, subchondral bone, synovium, ligaments, and surrounding muscles. The knee and hip are the most commonly affected joints, followed by the hands, spine, and foot. It typically develops gradually, most often in people over 45, and is more common in women than men. The traditional description, "wear and tear", implies that the joint is simply wearing out through use, like a tyre on a road. The traditional "wear and tear" model is misleading in two important ways. First, it suggests that the damage is inevitable and irreversible. Second, and more harmfully, it implies that use accelerates deterioration, which leads patients to move less, exercise less, and gradually lose the capacity that could protect them. Neither implication is accurate. The World Health Organization is explicit on this point: osteoarthritis is not an inevitable consequence of ageing. OA is better understood as a complex whole-joint disease involving changes in the joint's tissues and their ability to adapt to mechanical and biological stresses, driven by a combination of biological, mechanical, and lifestyle factors, many of which are modifiable.

Why Scans Don't Tell the Full Story

There is a well-established and poor correlation between the severity of OA based on plain radiograph changes and actual symptoms. Put simply: what shows up on an X-ray or MRI does not reliably predict how much pain you have, or how well you function. This matters enormously for how patients interpret their diagnosis. Articular cartilage itself is not innervated, so OA pain is thought to arise from other joint and surrounding tissues, including subchondral bone, synovium, capsule and ligaments. Structural findings on imaging are common in middle-aged and older adults with no symptoms at all. Evidence points to the presence of both peripheral and central nervous system sensitisation as sources of pain in osteoarthritis, which may explain why pain can become more severe and continuous over time, and why some people are more resistant to standard treatments. The practical implication: a scan showing cartilage changes is not a sentence. Imaging findings do not reliably predict the severity of symptoms in an individual person, and structural changes should always be interpreted alongside symptoms and physical function. Imaging findings alone should not be used as a reason to stop moving or exercising.

What Actually Drives Symptoms?

Several factors determine whether, and how severely, OA becomes symptomatic, and most of them are modifiable: Muscle weakness is common in people with OA and is associated with poorer symptoms and physical function. Knee OA patients have been consistently found to have weaker quadriceps muscle strength than healthy adults, and hip OA patients weaker hip abductor and knee flexor strength. In knee OA, lower quadriceps strength has been associated with greater risk of symptomatic and functional deterioration, although the evidence for structural progression is less clear. Strengthening can improve muscle capacity, physical function and symptoms, helping people tolerate and manage joint loading more effectively. Reduced activity levels create a damaging cycle: pain leads to reduced movement, which leads to deconditioning, which reduces the joint's ability to tolerate load, which increases pain. Breaking this cycle through structured, progressive exercise is one of the most strongly supported interventions for managing OA. Body weight has a direct mechanical relationship with joint load, particularly at the knee, where forces during walking are several times bodyweight. For people with osteoarthritis who are overweight or living with obesity, weight loss can reduce pain and improve physical function. NICE recommends supporting people with OA to lose weight where appropriate, noting that any weight loss is likely to be beneficial and that 10% weight loss is likely to provide greater benefit than 5%. Changes in pain processing, including features of peripheral and central sensitisation, may contribute to persistent or disproportionate pain in some people with OA, particularly in longer-standing cases. For people whose pain is persistent, distressing or associated with fear of movement or reduced confidence, pain education and psychological strategies can form useful parts of a broader OA management programme. Joint sensitivity and inflammation fluctuate over time. OA is not a steady, linear progression, it has periods of flare and relative calm, and understanding this can help patients interpret their symptoms more accurately and respond more adaptively.

Why Exercise Is Such an Important Treatment

This is the statement that surprises most patients with OA, and it is one most strongly supported by evidence. Exercise therapy is widely recommended for managing knee, hip, and hand OA, and consistent evidence supports that exercise therapy and specific strengthening exercise reduce pain and improve physical function in knee OA. It is recommended as a first-line treatment by every major international clinical guideline, including OARSI, NICE, and EULAR, as a core component of non-surgical management, alongside education and, where appropriate, weight management and other treatments. The concern that exercise accelerates joint damage is not well supported by the evidence. A systematic review found that long-term exercise did not worsen tibiofemoral radiographic disease severity, cartilage morphology, synovitis or effusion, although it found low-quality evidence of a possible increase in the odds of worsening bone marrow lesions, an area that warrants some caution and further research. Overall, appropriately dosed exercise reduces pain, improves function, and builds the muscular capacity that helps protect the joint from further stress. Both strengthening and aerobic exercise can improve symptoms and function, and combining different forms of activity can be a practical way to build fitness, strength and confidence. The best exercise is the one that is appropriate to your current capacity, progressive over time, and, critically, consistent.

Strength Training

Over half of the trials examining resistance training in knee OA found that symptoms, physical function, and strength were improved by clinically meaningful amounts compared to usual care. Strength training improves the capacity of the muscles surrounding the joint to absorb and distribute load, directly reducing the mechanical stress on the joint surface. Key muscle groups include the quadriceps, hip abductors, hamstrings, and gluteals. OARSI recommends strengthening, cardio, balance training, and neuromuscular exercise programmes as core recommendations for non-surgical management of knee and hip OA. Meaningful improvements usually require consistency over several weeks, and the programme should be progressed according to symptoms, capacity and goals.

Aerobic Exercise

Walking, cycling, swimming and aquatic exercise can all be useful options. Aerobic activity improves cardiovascular fitness, supports weight management and can contribute to better overall physical function. Aquatic exercise can be particularly useful when land-based activity is difficult because of pain, offering the benefits of movement with reduced joint loading, a useful starting point before transitioning to land-based activity.

Practical Strategies: What to Focus On

Start where you are. The biggest barrier to exercise for people with OA is the belief that pain during exercise means damage. A modest and temporary increase in symptoms during or after exercise can be acceptable. The important question is whether symptoms settle and whether the overall trend over time is improving rather than progressively worsening. This guided tolerance is very different from pushing through severe or persistent pain. Prioritise consistency over intensity. Consistency matters more than finding a perfect programme that you cannot maintain. Start at a manageable level and build gradually. Manage weight where relevant. Even modest reductions in bodyweight produce disproportionate reductions in joint load and pain. Diet and physical activity work synergistically here, and addressing both together produces better outcomes than either alone. Understand your flares. Periods of increased symptoms are a normal feature of OA, not evidence that the condition is rapidly worsening, and not a reason to stop exercising. Learning to distinguish a temporary flare from a signal that requires clinical review is one of the most useful things you can develop. Address the narrative. Understanding OA as a manageable condition rather than simply inevitable deterioration can help reduce fear and make it easier to remain active and engaged with rehabilitation.

How IP Physio Can Help

We begin by assessing the full picture: joint function, muscle strength, movement patterns, symptom behaviour, and the lifestyle and load factors contributing to your presentation. Where appropriate, we use objective strength testing to quantify strength deficits and monitor progress rather than relying solely on how strong you feel, because knowing exactly where your capacity falls short allows us to address it specifically rather than generically. From there, we build a structured programme that is realistic for your current level, progresses systematically, and is tailored to your specific joints and goals. We provide the education to help you understand what your scan findings do and do not mean, what is driving your symptoms, and how to interpret flares without fear. Our goal is not indefinite treatment. It is to build your understanding and physical capacity to the point where you are managing your OA confidently and independently, with less pain, better function, and a clearer sense of what the future looks like. If you have been told there is nothing to do but wait for a joint replacement, we would like to offer you a different conversation. Get in touch with us today.

References

• National Institute for Health and Care Excellence (NICE). Osteoarthritis in over 16s: diagnosis and management (NG226). 2022.
• World Health Organization. Osteoarthritis. Fact sheet. 2023. (528 million people living with OA globally in 2019.)
• Bannuru RR, Osani MC, Vaysbrot EE, et al. OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthr Cartil. 2019;27(11):1578–1589.
• Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis Care Res. 2020;72(2):149–162. doi:10.1002/acr.24131.
• Fransen M, McConnell S, Harmer AR, et al. Exercise for osteoarthritis of the knee: a Cochrane systematic review. Br J Sports Med. 2015;49(24):1554–1557. doi:10.1136/bjsports-2015-095424.
• Regnaux JP, Lefevre-Colau MM, Trinquart L, et al. High-intensity versus low-intensity physical activity or exercise in people with hip or knee osteoarthritis. Cochrane Database Syst Rev. 2015;10:CD010203. doi:10.1002/14651858.CD010203.pub2.
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• Culvenor AG, Ruhdorfer A, Juhl C, Eckstein F, Øiestad BE. Knee extensor strength and risk of structural, symptomatic, and functional decline in knee osteoarthritis: a systematic review and meta-analysis. Arthritis Care Res. 2017;69(5):649–658. doi:10.1002/acr.23005.