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How swimming can help to strengthen your knees

If you’re suffering from knee pain or injury, have you considered taking up swimming? This low-impact exercise builds up muscles around your knees and could help to ease your symptoms and have you feeling better all round.

Most of us will suffer from knee pain at some point, and it’s normally nothing to worry about. Common causes include injury or overuse, whether through playing sport or simply day-to-day life.

Arthritis is another common cause, with approximately 1 in 5 UK adults suffering from osteoarthritis of the knee.1

Although you might be tempted to stay away from exercise if you have a bad knee, it can often be one of the best ways to help it. Swimming, a low-impact activity that’s both accessible and affordable, is a great place to start.

Find out more about swimming to aid recovery from a knee injury

Is it safe to exercise if I have knee pain?

Firstly, if you have recurring or constant knee pain or swelling, especially if it’s stopping you from going about your daily life, you should speak to your doctor. They’ll be able to diagnose you and also give advice on if and when you should start exercising.


If your doctor has recommended exercise to rehabilitate and/or strengthen your knees, then it’s probably one of the best things you can do to feel better.

Swimming is a low-impact exercise that is commonly recommended for arthritis and other knee conditions.2

Why swimming is good for knee pain

When you swim, the buoyancy of the water supports your body weight, meaning less stress is placed on your joints, which can reduce the pain you feel.

At the same time, water provides more resistance than air, so as you move through the water your muscles are working harder than they feel like they are.3 Many people find swimming is a good way to exercise vigorously without hurting themselves.2

If you swim in warm water, you might also find that the temperature soothes your joints and eases your pain.3

Watch our video for more tips on managing joint pain

If you swim regularly, the muscles around your knees will build up, strengthening the support around your joint. This can not only relieve pain but also reduce the chance of pain in the future.

Swimming is also a great cardiovascular exercise, meaning it can help you to stay fit, burn calories and lose weight. Losing weight is one of the best things you can do to reduce knee pain. One study found that for every pound of weight lost, four pounds of pressure were taken off the knee joint.4

Other health benefits of swimming

Swimming is good for strengthening more than just your knees. It offers a whole-body workout, improving your fitness and muscle strength from head to toe. It can also improve your mobility, flexibility and endurance, as well as strengthen your core.

Regular swimming has been shown to reduce the risk of many illnesses, including heart disease, type 2 diabetes and stroke.5 There is evidence that swimmers live longer and stay fit for longer, and in children it has been shown to encourage development.6

Swimming has benefits for your mental wellbeing, too. It can boost your mood and reduce your stress levels. It has also been shown to help people sleep better.7

Other water-based exercises you could try

Swimming is great for you, but it’s not the only way to take advantage of the water to improve your health and strengthen your knees.


Hydrotherapy is physiotherapy that you do in a warm-water pool. The water supports you and the temperature can help your muscles relax.

It can offer benefits such as increased flexibility and improved strength and is often used to ease people back into exercise.

Water walking

Water walking is like regular walking, but you do it in a swimming pool. As with swimming, the water takes some of the strain off your knees, minimising your pain. Many people also find the temperature soothes their joints.

Because water provides more resistance than air, walking in water requires more effort, so it will burn more calories than a regular walk.3

Water aerobics

Water aerobics (also called aquatics or aquatic exercise) is popular among people with arthritis because classes offer an effective but low-impact workout. Many classes are set up specifically to help people with the condition.8

As with water walking, water offers increased resistance but takes the pressure of your knees.

How to get started

Before starting any new exercise regime, speak to your GP or consultant. They can help to give advice on the best course of action for your individual needs.

If you haven’t been in the habit of exercising, it’s important to start slow. Begin with gentle sessions and work up to longer and more frequent swims.

If you’re not a confident swimmer, look into lessons. A swimming instructor or physiotherapist can help you hone your technique and show you the best approach to strengthen your knees without hurting yourself.