TL;DR
- Walking and swimming both support knee health, but they load the joint very differently.
- Swimming reduces compressive load on the knee, making it useful for painful or arthritic joints.
- Walking helps maintain bone density, cartilage health and overall fitness for most healthy knees.
- The better choice depends on the specific knee condition, pain level and personal goals.
Knee pain is one of the most common reasons Australians cut back on exercise, and it is also one of the main reasons they ask whether they should be walking, swimming, or doing something else entirely. Both activities are widely recommended by general practitioners and physiotherapists, yet the advice often stops at general statements like “just keep moving”. For someone living with cartilage wear, a meniscus tear, or a knee replacement on the horizon, that level of guidance rarely feels enough.
The two activities are not interchangeable. Walking places repeated, weight-bearing load through the knee. Swimming offloads almost all of that body weight while still working the muscles around the joint. Each has clear benefits, and each has situations where it can make symptoms worse rather than better.
Dr Jonathan Negus is a specialist knee surgeon in Sydney who regularly sees patients trying to balance staying active with protecting a sore or recovering knee. Both activities have clear benefits and clear limitations, and the right choice often depends on the specific knee condition, current pain levels, and the goals someone is trying to achieve.
General information only and not a substitute for personalised medical advice. Anyone with persistent knee pain, swelling or instability should speak with a qualified health professional before starting or changing an exercise programme.
How Walking and Swimming Load the Knee Differently
The biggest difference between the two activities is the way they transfer force through the knee joint. Understanding that difference is the starting point for every other decision about which one suits a particular knee.
Compressive load during walking
Walking on flat ground typically transmits forces of around two to three times body weight through the knee with each step. Going up or down stairs, walking on slopes, or carrying shopping increases that further. For a healthy joint, this kind of repetitive loading is helpful: it stimulates cartilage nutrition, supports bone density, and keeps the surrounding muscles working. For a knee with significant cartilage damage or recent surgery, the same forces can drive pain and swelling.
Reduced load during swimming
Water immersion to chest height removes roughly 60% of body weight from the joints, and immersion to the neck removes around 90%. Swimming therefore allows the knee to move through full flexion and extension without the compressive forces seen during walking. The trade-off is that the bones and cartilage receive less of the loading they need to stay strong, which is why swimming is rarely the only activity recommended for long-term knee health.
Muscle activation during walking
Walking activates the quadriceps, hamstrings, calves, and gluteal muscles in a coordinated, weight-bearing pattern that mirrors daily life. The pattern of muscle work during walking closely matches the demands of standing, climbing stairs, and rising from a chair, which is why walking is so useful for maintaining day-to-day knee function.
Muscle activation during swimming
Swimming, particularly freestyle and backstroke, works the hip flexors, hamstrings, and core, with less direct quadriceps engagement than walking. Breaststroke is a notable exception: the kicking action places rotational stress through the knee and can aggravate symptoms in some patients.
Benefits of Walking for Knee Health
Walking is the default exercise recommendation for most adults because it is accessible, free, and broadly safe. For knees specifically, the benefits go beyond simple cardiovascular fitness.
Cartilage nutrition through gentle loading
Articular cartilage has no direct blood supply. It receives nutrients through the rhythmic compression and decompression of joint fluid that happens during weight-bearing activity. Regular walking helps maintain that exchange, which is associated with better cartilage health over time.
Bone density and lower-limb strength
Walking is a load-bearing activity that helps preserve bone mineral density in the femur, tibia, and hip. It also maintains baseline strength in the quadriceps and calves, which is important for knee stability. Patients who stop walking entirely after a knee injury often lose strength faster than they expect.
Cardiovascular fitness and weight management
Every kilogram of body weight lost is associated with up to four kilograms less force through the knee with each step. Walking is one of the most sustainable ways for most Australians to manage weight long term, and weight management remains one of the most evidence-based interventions for knee osteoarthritis.
Ease of routine and long-term adherence
Walking is easy to fit into daily routines, can be done with others, and rarely requires special equipment beyond supportive footwear. Programmes patients actually stick with tend to deliver better outcomes than ideal programmes they abandon, and walking has one of the highest long-term adherence rates of any exercise. Walking outdoors is also associated with improved mood and reduced stress, which supports long-term consistency.
Benefits of Swimming for Knee Health
Swimming has a different role. It is rarely the first activity prescribed for a healthy knee, but it can be the most useful option for a knee that cannot tolerate full weight-bearing exercise.
Offloading painful or arthritic joints
For patients with moderate to severe knee osteoarthritis, walking long distances can flare up pain for hours afterwards. Swimming and water-based exercise allow the same cardiovascular workout with a fraction of the joint load, which often means more movement is possible without a pain rebound.
Moving through full range without impact
Water resistance allows the knee to move through flexion and extension against gentle resistance, without the impact of foot strike. This can be particularly helpful in the early weeks after arthroscopic surgery or during a flare of inflammatory arthritis, where keeping the joint moving matters more than loading it.
Conditioning the whole body with low spinal load
Swimming works the upper body, core, and lower body together, which helps maintain overall fitness when walking distances are limited. It also reduces compressive load through the lumbar spine, which matters for the many patients who have both knee and back symptoms.
How Each Activity Suits Common Knee Conditions
The right answer depends heavily on what is going on inside the knee. The notes below describe general patterns seen in clinical practice, but they are not a substitute for an individual assessment. Patients with ongoing symptoms benefit from a tailored review of their non-surgical treatment options before committing to a long-term exercise plan.
Knee osteoarthritis
Mild to moderate osteoarthritis often responds well to a combination of walking and strengthening, with swimming used on higher-pain days or as a supplementary activity. More advanced osteoarthritis, where walking provokes significant pain or swelling, often shifts the balance towards swimming or hydrotherapy as the main aerobic activity, with walking kept short and flat.
Patellofemoral pain
Patellofemoral pain, sometimes called runner’s knee, often improves with shorter walking distances on flat ground combined with quadriceps and hip strengthening. Long walks on slopes or stairs may aggravate symptoms. Swimming is generally well tolerated, although breaststroke kick can sometimes worsen front-of-knee pain.
Meniscus tears
Stable meniscus tears that are managed without surgery often respond to short, regular walks and progressive strengthening, with swimming as a low-impact alternative on sore days. Larger or unstable tears, particularly those causing locking or giving way, usually need a specialist review before any structured exercise programme is started.
How to Choose Between Walking and Swimming
There is rarely a single right answer. For many patients, the best programme combines both activities and adjusts the ratio based on how the knee responds. A few practical questions can help guide that decision.
Tracking pain during and after activity
A useful rule is the 24-hour rule: if pain or swelling is worse the day after an activity than it was beforehand, the dose was probably too high. Walking that consistently breaches this rule may need to be shortened, slowed, or partially replaced with swimming until the joint settles.
Matching activity to goals and lifestyle
Patients training for a hike, returning to work that involves standing, or trying to maintain bone density usually need walking somewhere in the programme. Patients whose main goal is to stay aerobically fit while managing severe arthritis pain may get more benefit from swimming as the primary activity.
Weighing access, cost, and consistency
Walking requires only supportive shoes and a safe footpath, while swimming requires reasonable access to a pool. The activity that fits more easily into someone’s week is usually the one that gets done. Consistency matters more for joint health than the choice of activity in isolation.
Many Sydney patients do well with a mixed weekly programme, for example three to four short walks combined with one or two pool sessions. This pattern allows the joint to receive enough loading to support cartilage and bone health while keeping overall pain and swelling under control.
How to Protect Your Knees During Either Activity
Both activities can be made safer and more comfortable with a few small adjustments. The aim is to make movement easier to repeat, not harder to start.
Choosing the right footwear and walking surface
Supportive shoes with adequate cushioning are associated with reduced peak knee loading compared with worn-out or unsupportive footwear. Flatter, softer surfaces such as grass, athletics tracks or smooth bitumen are usually kinder to a sore knee than concrete footpaths or steep hills.
Selecting knee-friendly strokes in the pool
Freestyle and backstroke are usually the most knee-friendly strokes because the kick is straight and the rotational forces through the knee are low. Breaststroke, which uses a whip-kick motion, can aggravate medial knee pain and patellofemoral symptoms in some swimmers. Switching strokes is often enough to resolve pool-related knee pain.
Warming up and progressing gradually
A few minutes of easy movement at the start of either activity allows the joint fluid to warm and distribute, which is associated with reduced stiffness and pain. Distances and durations are best increased by no more than around 10% per week to give the knee time to adapt.
Neither walking nor swimming on its own builds enough muscle strength around the knee for most patients with ongoing pain. Adding two or three short strengthening sessions per week, focused on the quadriceps, hamstrings, and hip muscles, is one of the most consistently helpful changes a patient can make alongside either activity.
When to Seek Specialist Input for Knee Pain
Most everyday knee niggles settle with sensible activity changes and time. Some symptoms, however, are worth a closer look. Patients with persistent or worsening symptoms despite reasonable self-management often benefit from a specialist review of their knee osteoarthritis or other underlying condition.
Pain that does not settle
Knee pain that persists for more than six weeks despite activity modification, simple analgesia and basic strengthening usually warrants further assessment. Imaging and a structured examination can help clarify whether the cause is mechanical, inflammatory or referred from elsewhere.
Pain alongside swelling, locking or giving way
Recurrent swelling, episodes of the knee locking in one position, or feelings of the joint giving way during walking are signals that something inside the joint may be unstable. These symptoms are commonly seen with meniscus tears, ligament injuries or loose fragments of cartilage, and a specialist review is generally recommended.
Pain that limits daily life
Pain that interferes with sleep, work, or basic activities such as climbing stairs or rising from a chair is rarely a problem that resolves on its own. Earlier specialist input often allows more conservative options to be explored before surgery becomes the main consideration.
Choosing the Right Activity for Your Knees
Walking and swimming are both valuable for knee health, and for most patients the question is not which one to choose but how to combine them. Walking offers the loading the joint needs to stay strong; swimming offers the relief the joint needs when symptoms flare. The right balance depends on the specific condition, the level of pain, and what fits realistically into someone’s week.
Patients in Sydney who are unsure how to structure their exercise around an existing knee problem, or who feel their current routine is no longer working, are welcome to book a consultation with Dr Jonathan Negus at his rooms. A tailored assessment can clarify what is going on inside the knee and help map out a sensible plan that protects the joint while keeping movement part of daily life.
Disclaimer: The information provided is general in nature and is intended for educational purposes only. It is not a substitute for personalised medical advice, diagnosis or treatment from a qualified health professional. Readers should seek advice from their general practitioner or a specialist knee surgeon before acting on any information presented. Dr Jonathan Negus and his practice accept no responsibility for outcomes arising from reliance on this information.
Frequently Asked Questions (FAQs)
1. Is walking bad for arthritic knees?
Walking is not generally bad for arthritic knees and is often recommended as part of conservative management for knee osteoarthritis. Pain that consistently increases the day after walking suggests the dose is too high rather than that walking itself is harmful. Shorter distances on flat ground, supportive footwear and gradual progression typically allow most patients with mild to moderate arthritis to keep walking comfortably.
2. Can swimming alone keep my knees healthy?
Swimming is excellent for cardiovascular fitness and joint mobility, but it does not provide the weight-bearing load that helps maintain bone density and stimulates cartilage nutrition. Most knee specialists suggest combining swimming with some form of land-based activity, such as walking or strengthening exercises, where it is tolerated. Patients who cannot weight bear at all are an obvious exception and may rely more heavily on pool-based exercise.
3. Which is better after a knee replacement, walking or swimming?
Walking is usually the cornerstone of recovery after a total knee replacement and is encouraged from the first day post-operatively. Swimming is typically reintroduced once the surgical wound has fully healed, often around six weeks after surgery, and can complement walking rather than replace it. The exact timing should be confirmed with the treating surgeon, as it can vary depending on the procedure and individual healing.
4. Does breaststroke damage the knees?
Breaststroke uses a whip-kick action that involves rotation through the knee, and it can aggravate medial knee pain or patellofemoral symptoms in some swimmers. It does not directly cause structural damage in most healthy knees, but patients with existing meniscus or cartilage problems often find breaststroke uncomfortable. Switching to freestyle or backstroke is a simple way to reduce knee load in the pool.
5. How many steps a day is good for knee osteoarthritis?
There is no single step count that suits every knee. Research in patients with knee osteoarthritis suggests that gradually increasing from a baseline by around 1,000 extra steps per day is associated with improved function over time. The best target is one that allows steady progress without flaring symptoms the following day, and it is usually built up over weeks rather than chased from the start.
6. Is water walking as good as swimming for knees?
Water walking is a useful middle ground between land-based walking and swimming. It provides some weight-bearing stimulus while reducing peak joint loads through buoyancy, and it can be more accessible than swimming for patients who are not confident in deep water. Many hydrotherapy programmes use water walking as their main activity for patients with significant knee arthritis.
7. Should I stop walking if my knee hurts the next day?
Mild stiffness or low-level soreness the day after walking is common and usually settles within 24 hours. Pain or swelling that is clearly worse the next day, or that lasts longer than 24 hours, suggests the activity dose was too high. Reducing distance, slowing the pace, switching to a flatter route, or replacing some walks with pool sessions for a week or two often allows the knee to settle without stopping exercise altogether.
8. When should I see a knee surgeon about my pain?
A specialist review is generally appropriate when knee pain has lasted more than six weeks despite sensible activity changes, when there is recurrent swelling, locking or giving way, or when symptoms are limiting work, sleep or daily activities. Earlier review tends to widen the range of non-surgical options that can be considered before surgery becomes the main focus.
