10 easy knee-strengthening exercises

Why do my knees hurt?

Many people experience pain in their knees, especially as they get older. You may notice your knees ache when you kneel or climb stairs. It’s often due to overuse, arthritis or injury.

If you have knee problems or pain, you might want to avoid exercising. However, gentle knee exercises can improve your symptoms, prevent stiffness and help you stay active.

Speak to a GP if your knee pain does not improve after a few weeks.

Call NHS 111 if your knee is very painful or swollen, you cannot move it or put weight on it, or there is redness, discolouration or heat around the joint.

How to strengthen knees 

You can reduce the risk of knee pain by performing strength exercises to help strengthen the muscles around your knees. 

Stronger muscles provide more support to the knee by reducing pressure and strain on the joint. This can relieve pain, improve stability and reduce the risk of injury.

Stretching can also help keep the muscles flexible and improve mobility in the knee joint.

Knee replacement and arthritis: exercises to avoid

Some people with knee pain should avoid performing high-impact exercises, which are movements where you move both feet off the ground at the same time, such as running or skipping. This includes people:

• who have had a knee replacement in the last 3 to 6 months
• with severe osteoarthritis
• who experience sharp knee pain or swelling.

Instead, low-impact activities like walking, swimming, stationary cycling and using an elliptical machine can help you get stronger without putting too much stress on your knees.

The exercises below are low-impact exercises designed to build strength and flexibility to help reduce knee pain.

If your knee pain is caused by an injury or a health condition, or you’ve recently had surgery, make sure to speak to a healthcare provider before you start any new exercise programme.

Exercises to target the knee joint

You can watch me demonstrate 10 knee-strengthening exercises and stretches below, alongside cardiac rehab participant Elizabeth Nathan.

Before you start, it’s a good idea to warm up with light exercise by marching gently on the spot or following our 15-minute warm-up routine.

Aim to perform this knee-strengthening routine 3 to 4 times a week. Make sure to leave at least 1 day between workouts to rest.

If you need to, you can hold on to a chair or a wall for balance. As your strength improves, you can gradually perform more repetitions of each exercise.

While you should feel some tension in your muscles when doing these exercises, they should not feel painful.

Check with your doctor before you start if you’re new to exercise or think these exercises could worsen an existing medical issue or injury.

And stop immediately and contact your GP if you feel unwell, very short of breath, chest pain, dizziness or heart palpitations while exercising.

Seated knee exercises

1. Knee extensions

1. Sit on a chair with your feet hip-width apart and your back straight.
2. Slowly lift 1 foot out in front of you until your leg is straight.
3. Hold the leg up for 10 seconds, then slowly lower it back down.
4. Repeat 10 times on each leg.

Tip: If you cannot fully straighten your leg, keep the leg bent and lift the knee straight up to perform a knee raise instead.

2. Calf raises

1. Sit on a chair with your feet hip-width apart.
2. Push through the balls of your feet and lift both heels as high as you can.
3. Hold your heels up for 3 to 5 seconds while squeezing your calf muscles.
4. Slowly lower both heels back to the ground.
5. Repeat 8 to 12 times.

Next step: Try the exercise standing up while holding the back of a chair.

Standing knee exercises

3. Sit to stand

1. Sit on a sturdy chair with your feet hip-width apart and flat on the ground and your knees bent at a 90-degree angle.
2. Cross your arms over your chest and stand up without using your hands.
3. Sit down slowly.
4. Repeat 5 to 15 times.

Tip: Use your hands to help you stand up if you need to.

4. Hamstring curls

1. Stand hip-width apart with your hands by your side or on your hips.
2. Lift 1 heel towards your bottom as far as you can while keeping your thighs still and knee pointing down.
3. Hold your heel up for 5 seconds before lowering it back to the ground.
4. Repeat 6 to 16 times on each leg.

Tip: If you feel wobbly, stand behind a chair and hold onto the back for balance.

5. Step ups

1. Stand hip-width apart in front of a stable step or at the bottom of some stairs.
2. Step your right foot on to the step in front of you.
3. Step your left foot onto the step.
4. Return your right foot back to the ground, followed by your left foot.
5. Repeat with each leg starting the movement 10 to 30 times.

Tip: Hold on to a banister or the back of a chair if you need to.

Floor knee exercises

You can perform these exercises lying down on an exercise mat if you feel confident getting up and down from the floor. If not, you can do them lying on a firm bed instead.

6. Clamshells

1. Lie on your side with your knees bent in front of you.
2. Slowly lift the top knee up towards the sky so the hip rotates slightly, without moving your pelvis or torso.
3. Slowly return the leg to the starting position.
4. Repeat 5 to 15 times on both sides.

7. Bridges

1. Lie on your back with your knees bent and feet on the floor or bed.
2. Press into your feet and lift your hips up as far as feels comfortable while tensing your stomach muscles and keeping your shoulder blades on the ground.
3. Slowly lower your hips while tensing the muscles in your bottom.
4. Repeat 5 to 15 times.

8. Leg lifts

1. Lie on your back with 1 leg bent at the knee and the other leg straight.
2. Lift your straight leg up just off the floor or bed.
3. Hold the leg up for 5 seconds.
4. Slowly lower your leg back down.
5. Repeat 5 times on each leg.

Knee stretches

These stretches target the muscles surrounding the knee joint to help prevent stiffness and make it easier to move your knee.

• Try more stretches to improve your flexibility or these chair-based mobility exercises.

1. Hamstring stretch

1. Stand hip-width apart.
2. Place 1 heel forwards, keeping the knee straight.
3. Push your hips backwards as if sitting down slightly and move your upper body forwards, keeping your back straight.
4. Rest your hands on your bent leg and hold the stretch for 20 to 30 seconds.
5. Repeat on the other side.

Tip: You can also perform the stretch sitting down.

2. Quadricep stretch

1. Stand hip-width apart, holding on to the back of a chair or the wall for support.
2. Bend your knee to bring your foot towards your bottom.
3. Hold on to the ankle with 1 hand and pull your heel towards your bottom to feel a stretch at the front of your thigh.
4. Hold for 20 to 30 seconds.
5. Slowly lower your foot back to the ground.
6. Repeat on the other side.

Tip: If your hand cannot reach your foot, loop a towel or resistance band around your foot.

• Try our 10-minute cool-down routine after you finish exercising to prevent stiffness and lower your heart rate gradually.

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