10 Exercises to Strengthen the Knees

Whatever your exercise of choice—running, walking, weightlifting, or Pilates— the health and strength of your knees is crucial. Knees bear your body weight, allow for the full range of motion of your legs, and create stability; however, they are often prone to injury. Strengthening
your knees is essential for mitigating damage and keeping your body strong and pain-free.

The knees are a complex system of joints that support the body. Strong knees make a difference in everyday life, and incorporating knee-strengthening exercises into your workout regime is vital for your well-being—the following 10 exercises to keep your knees in top shape.

Beginner Exercises for Knee Strength

These three beginner moves can make you comfortable with knee movement before moving on to more advanced exercises.

Leg Lifts

Leg lifts strengthen your quadriceps and avoid putting any pressure on the knee. According to the National Health Service, you can add ankle weights to raise the intensity or sit in a chair to reduce it.

1. Lie on your back.
2. Bend one knee and keep the other straight on the floor.
3. Lift the straight leg to match the height of the bent knee.
4. Repeat 10 times.
5. Switch legs.
   

Bridges

The bridge is a popular yet simple exercise to strengthen your glutes. Strong glutes can alleviate pressure off your knees when you walk or run.

1. Lie on your back.
2. Bend your knees and flatten your feet on the floor.
3. Lift your hips up as you squeeze your glutes tight.
4. Hold this position for 5 seconds.
5. Lower yourself back to the starting position.
6. Repeat 10-15 times.

Calf Raises

Calf raises can be performed on a flat surface or a step for a deeper stretch. If stability is a challenge, place your hands flat against a wall.

1. Stand with your feet hip-width apart.
2. Slowly raise your body onto your toes.
3. Lower back down to the starting position.
4. Repeat 15-20 times.

Intermediate Exercises for Knee Strength

The following intermediate-level exercises target the major muscles surrounding the knee (quads and hamstrings), increasing strength, stability, and flexibility.

Step-ups

Step-ups target the quadriceps, and strong quads can reduce the load on your knees.  

1. Stand in front of a step or bench.
2. Step up with one foot.
3. Step up with the other foot.
4. Step down in the same order you stepped (e.g., if you stepped with your right foot first, then your left foot, step down in that order.)
5. Repeat 10 times.

Single-Leg Stands

To increase intensity when performing single-leg stands, close your eyes or stand on an unstable surface, like a small trampoline.

1. Stand on one leg for 30-60 seconds.
2. Switch legs.

Wall Sits

Wall sits work your entire leg, targeting the quadriceps, hamstrings, and glutes.

1. Stand with your back against a wall.
2. Slide down into a seated position as if sitting in a chair.
3. Hold for 20-30 seconds.
4. Repeat five times.

Advanced Exercises for Knee Strength

Performing the following exercises can help reduce the risk of knee injuries by increasing
support and shock absorption during your daily physical activities.

Squats

Squats strengthen the glutes, quadriceps, and hamstrings.

1. Stand with your feet hip-width apart.
2. Bend your knees.
3. Lower your body as if you were sitting down.
4. Keep your back straight and knees directly over your ankles for proper form. Try to form a 90-degree angle between your knee and ankle.
5. Push back up to the starting position using your glutes.
6. Repeat 10 times.
   

Lunges

Lunges work the same muscles as squats and improve balance to prevent knee injury.

1. Stand with one foot forward and the other back.
2. Bend your knees.
3. Lower your body until your front knee is in line with your ankle.
4. Push back up to the starting position using your leg and glutes.
5. Switch legs.
6. Repeat 20 times. (10 times per leg.)

Hamstring Curls

Hamstring curls are an advanced movement that can take time to perfect. Once you feel comfortable with them, you can make them more challenging by adding ankle weights. You can perform them using a leg curl machine or standing with a chair.

1. Stand and hold onto a chair.
2. Bend one knee and bring your heel back toward your glute.
3. Lower it back down to the starting position.
4. Switch legs.
5. Repeat 10 times on each leg.

Resistance Band Lunges

You will need a resistance band for this exercise, which helps to add resistance and isolate the muscle.

1. Position band under right leg.
2. Stand with right leg forward and left leg back.
3. Keep the tension on the band and lower into a lunge until both knees are 90 degrees.
4. Return to start.
5. Repeat 16 reps on each side.

5 Reasons to Strengthen the Knees

Weak knees can increase the risk of sprains, strains, and severe conditions like osteoarthritis. Building up the muscles surrounding the knees can improve overall leg health and increase mobility and stability. These are science-backed reasons why you should focus on increasing knee strength:

Promotes Joint Support

Strong muscles around the knee (quadriceps, hamstrings, and calf muscles) help stabilize the joint and reduce the risk of injuries, such as meniscus injuries, tendinitis, and ligament tears. In an observational study, researchers found that a low-load knee exercise regime can enhance joint function and increase muscle strength. It can also create pain-free walking and improve physical health, quality of life, and social well-being.

Improves Balance

Strengthening exercises improve balance and range of motion, which can help prevent you from critical falls. In a randomized control trial, researchers evaluated symptomatic and asymptomatic participants with knee osteoarthritis to evaluate if physical exercise makes a difference in balance. Results showed significant improvement in the symptomatic knee group, especially in pain and function; the asymptomatic group also experienced significant reductions in time to complete a step-up test. These findings suggest that physical exercise, such as knee-strengthening movements, can positively affect balance and functionality.

Increases Mobility

Strong knees are essential for daily physical activities, including walking, grocery shopping, picking up children, and standing up and down. In a study with multiple sclerosis participants, researchers found that resistance exercise (see elastic band exercise above) is a functional intervention that can improve knee mobility and muscle strength in a short period.

Reduces Stress on the Body

Maintaining strong knee muscles can help manage the stress of body weight. In a systematic review, researchers found that resistance training with blood flow restriction (see elastic band exercise above) can reduce joint stress, increase quadriceps muscle mass, and improve functionality in patients with knee osteoarthritis.

Delays Age-Related Degeneration

Strong muscles work to preserve cartilage health and delay degenerations associated with aging. In a recent systematic review, researchers found that exercise is a worthwhile therapy capable of mitigating cartilage degeneration, reducing inflammation, and preserving bone structure. In addition, fitness training is shown to reduce pain, stiffness, and joint dysfunction.

Strengthening the knees is a vital part of your workout routine, as it helps prevent injuries and maintain overall health and well-being. When you improve your mobility and keep your joints flexible, you can perform your daily activities to the best of your ability. As always, you should seek the approval of a medical professional when beginning any workout, especially if you are prone to injury.