Knee osteoarthritis is a common condition affecting millions of people around the world. It often causes pain, stiffness, and limits mobility, making everyday activities like walking, climbing stairs, or even standing for long periods quite challenging. Despite these difficulties, there is encouraging news: targeted exercise can be a highly effective, non-surgical way to ease symptoms and improve knee function.

In this article, we’ll explore the five best exercises to help strengthen and stabilise knees affected by osteoarthritis. These exercises are safe, straightforward, and practical—whether you prefer working out at home or in the gym.

Understanding Osteoarthritis of the Knee: Why Exercise Matters

Osteoarthritis occurs when the cartilage—the smooth, cushioning tissue between bones in the knee joint—wears away over time. This loss of cartilage results in pain, swelling, stiffness, and a reduced range of movement, making simple daily tasks harder.

Regular, targeted exercise plays an essential role in managing these symptoms. Research shows that exercising can reduce pain, build up the muscles supporting the knee, and slow the progression of the disease. Stronger muscles help stabilise the joint and ease pressure on the worn cartilage. Additionally, gentle cardiovascular exercise promotes blood flow and keeps joints healthy. Trusted health organisations, like the NHS and physiotherapists, recommend combining strengthening exercises with low-impact cardio for the best results.

As researchers Baker and McAlindon (2000) explain, “many of the factors that lead to disability can be improved with exercise.” This highlights how exercise does more than just reduce pain; it also helps people maintain their independence.

Similarly, Howe (2016) points out that “international clinical guidelines recommend exercise for the treatment of osteoarthritis,” reflecting a global consensus on its importance.

Petrella (2000) adds that “exercise is considered an important non-pharmacological approach” to managing knee osteoarthritis, meaning it is a key treatment alongside medication.

Key Principles: How to Exercise Safely with Osteoarthritis

When exercising with osteoarthritis, your safety is the most important consideration. It’s normal to feel some mild discomfort during movement, but sharp pain or worsening symptoms are signs you should stop and rest.

Start slowly, gradually increasing how long and how hard you exercise. Avoid exercises that place too much strain on your knees, such as running, jumping, deep squats, or twisting movements—these can worsen joint damage.

It’s always wise to check with a healthcare professional before beginning a new exercise routine, especially if you’re older or unfamiliar with exercise. They can recommend safe, evidence-based exercises tailored to your needs.

Remember, “both aerobic and strength training have been examined as treatments for knee osteoarthritis, with considerable variability in the results,” which means it’s important to find exercises that work well for you personally.

The 5 Best Exercises for Strengthening Arthritic Knees

Here are the five most effective exercises for strengthening knees affected by osteoarthritis. They are simple, safe, and have proven benefits.

1. Straight Leg Raises
Lie on your back with one leg bent and the other straight. Slowly lift the straight leg until it’s level with the bent knee, hold for a few seconds, then lower it gently.
This exercise strengthens the quadriceps—the large muscles at the front of your thigh—without putting weight on your knee, making it ideal for beginners or those exercising at home. (See picture below.) Aim for 10 to 15 repetitions on each leg.

2. Seated Knee Extensions
Sit on a chair with both feet flat on the floor. Slowly straighten one leg out in front of you, hold the position for 3–5 seconds, then lower it back down.
This also targets the quadriceps and can help improve knee movement. Beginners will find it accessible, and if appropriate, light ankle weights can be added later for a challenge.

3. Step-Ups
Using a firm step or low bench, step up with one foot, then bring the other foot up to join it. Step down in the same order.
Step-ups help build thigh strength and improve balance and knee stability. Make sure the step is secure, and use a handrail if needed for extra support. This exercise can be done indoors or at the gym.

4. Wall Slides
Stand with your back against a wall and your feet shoulder-width apart. Slowly bend your knees, sliding your back down the wall a few inches, keeping your knees behind your toes. Hold briefly, then slide back up.
Wall slides strengthen your quadriceps and improve control of your knee joint. Avoid going too deep to prevent strain.

5. Gentle Stationary Cycling
Cycle on a stationary bike at low resistance for 10 to 15 minutes at a gentle pace.
Cycling is a great low-impact exercise that improves joint movement and muscle endurance without harsh impact on the knees. It’s an excellent warm-up or cardio complement to strengthening exercises.

It’s essential to focus on proper form during every exercise to avoid injury. Start with slow, controlled movements and gradually increase repetitions as your strength and confidence grow. Howe (2016) emphasises that “most forms of exercise have been demonstrated to have significant positive effects on pain and function at the end of the exercise programme.”

Petrella (2000) also highlights how “regular exercise can improve pain control, proprioception (your sense of body position), strength, instability, and endurance,” all of which help people maintain their independence.

Exercises to Avoid: Protecting Your Knees from Harm

Certain exercises can make osteoarthritis symptoms worse and should be avoided. These include:

• High-impact activities such as running or jumping, which place excessive force on the knee joint.
• Deep squats and lunges, which overload the cartilage.
• Twisting or pivoting movements, which can cause pain and instability.

As Baker and McAlindon (2000) remind us, “treatments have been more successful at decreasing pain rather than disability,” so knowing which osteoarthritis exercises to avoid is just as important as knowing which to do. Choosing safe, low-impact exercises will protect your knees while still enabling progress.

Building a Knee-Friendly Exercise Routine: Tips for Success

Building an effective exercise routine for your knees means practising your chosen exercises three to four times a week. Begin with one to two sets of 10–15 repetitions, then slowly increase as you grow stronger.

Include low-impact cardio exercises, such as gentle cycling or swimming, to improve heart health and joint mobility without adding strain. Research shows that “a majority of the studies had a positive effect on pain and/or disability,” reinforcing how exercise can make a real difference.

Petrella (2000) encourages continued exercise as “a mainstay of non-pharmacological treatment of osteoarthritis of the knee.”

Use resources such as NHS and physiotherapy exercise guides that offer clear instructions and helpful images.

Howe (2016) cautions that “unless participants continue the programme, the sustainability of these effects in the longer term are questionable.” Consistency is vital—small, regular efforts will add up to stronger knees, less pain, and better day-to-day function.

Conclusion

Targeted exercise is a powerful way to manage knee osteoarthritis. By strengthening muscles, improving stability, and reducing pain, these five exercises can help you reclaim mobility and enjoy a better quality of life.

Always prioritise safety, listen to your body, and seek professional advice when needed. Make these exercises part of your regular routine and take confident steps towards healthier, happier knees.

References

Baker, K., & McAlindon, T. E. (2000). Exercise for knee osteoarthritis. Current Opinion in Rheumatology, 12(5), 456-463.

Howe, T. (2016). Exercise for osteoarthritis of the hip and knee. Annual Review of Gerontology and Geriatrics, 36(1), 155-168.

Petrella, R. J. (2000). Is exercise effective treatment for osteoarthritis of the knee? British Journal of Sports Medicine, 34(5), 326-331.