Folks with bad knees can’t just do any leg exercise.

Doing the wrong leg exercises will put extra strain on the knees and increase knee pain.[ref]A Complete List Of Bodyweight Leg Exercises (Beginner to Advanced), FocusFitness[/ref]

The exercises I’m about to share with you aren’t for treating knee pain – they’re low-impact exercises which won’t make your knee problem worse. That said, these exercises are known to strengthen the knees and even reduce pain.

Note that all knee problems are not the same – some are more severe than others. So listen to your body and stick to exercises you’re comfortable with. The worst thing you can do is to train through pain. Stop whenever you feel unusual sharp pain.

In this article, I will share exercises that can strengthen your hamstrings, quadriceps, glutes and calf muscles.

Best Leg Exercises For Bad Knees

These exercises put less strain on the knees and will activate all leg muscles. Don’t do high reps – limit your reps to a maximum of 15 per set.

1. Reverse Lunge

This is an effective lunge variation for strengthening the quadriceps, hamstrings and the glutes. Unlike the forward lunge, this variation allows you to control alignment as you step backwards. Stepping backwards will also improve your balance.

How To Perform

• Stand upright with hands on the side or place them on the waist.
• Step backwards with one foot then lower the rear knee until it almost touches the floor – go as low as you feel comfortable.
• Perform the exercise slowly to avoid hitting the floor with the rear knee. And make sure the front knee doesn’t go past the toes.
• Slowly rise until the front knee is straight, and then repeat several times. Do the same number of reps for each leg.

 2. Box Squats

You need a sturdy chair or a box to perform this exercise. Do the exercise slowly to activate the quadriceps fully.

How To Perform

• Stand a step away from a chair, facing away from it and keep the feet shoulder-width apart.
• Bend the hips and lower yourself until the butt rests on the chair. Then slowly rise without pushing yourself off the chair.
• You have to control your motion to benefit from this exercise. It won’t be helpful if you do it fast.

 3. Standing Calf Raises

This exercise will help build the stubborn calf muscles. Note that the calf muscles support the knees so strengthening them will increase knee strength.

This is a low impact exercise which means you can do it every day.

How To Perform

•  Stand with your feet a few inches apart and keep the legs straight.
• Raise the heels as high as you can – only the balls of the feet and toes should be on the floor.
• Hold that position for 3 – 5 seconds and repeat 10 times.
• If this exercise is too easy for you, perform it on one leg. You’ll activate the calves more. Feel free to hold on to a table or pool for support if you lack balance.

 4. Side-Lying Leg Lifts

This exercise mainly works the adductor and hip muscles. The adductor muscles are responsible for moving the thighs side of the body. Strengthening them will improve your movement and athletic performance.

How To Perform

• Lie sideways and keep the body straight. Stretch out the bottom hand and place your head on it.
• Raise the top leg as high as possible then slowly lower it to starting position to complete the rep.
• Repeat this movement several times and do the same number of reps for each leg.
• You can wear an elastic band on the thighs to make the exercise more challenging.

 5. Seated Leg Extensions

Doctors usually advise against machine leg extensions when someone has knee problems, but seated leg extensions are totally safe. In fact, they’ll strengthen the knees.

This exercise mainly targets the quadriceps.

How To Perform

• Sit upright on a chair and keep the knees bent at a 90-degree angle.
• Slowly lift one leg and straighten it as you engage the quadriceps.
• Keep leg straight for 3 seconds as you tighten the quadriceps.
• Slowly lower the leg to starting position and repeat. Complete reps for one leg then switch.

 6. Glute Bridges

I’ve talked about the glute bridges in numerous articles[ref]The Only 7 Bodyweight Exercises You Need To Build Muscle and Strength, Focus Fitness[/ref]. They activate the glutes, hamstrings, lower back and ab muscles.

How To Perform

• Lie flat on your back and place hands on the side.
• Bring your calves close to the thighs until the ankles are directly below the knees.
• Using the support of your arms – slowly lift your butt off the floor and raise the hips as high as you can. Hold the top position for 2 or 3 seconds then slowly lower the butt to the floor and repeat.
• Performing this exercise on one foot will make it more challenging.

 7. Standing Hamstring Curls

This is a simple exercise and most beginners should be able to do it. And it can also be done while lying on the stomach. It targets the hamstrings and glute muscles.

How To Perform

• Stand on one foot – grab a table or a wall for support.
• Bend the other leg backwards and bring it as close to the thigh as possible.
• Hold the top position for 2 seconds then slowly lower it to starting position and repeat.

You can also perform this exercise while lying.

• Lie flat on your stomach then bend both feet and bring them close to the thighs.
• Then slowly straighten them and repeat.

Hamstring curls don’t put any pressure on the knee and they’re one of the best exercises for someone with severe knee pain.

8. Single Leg Deadlift

The single leg deadlift will strengthen hamstring and glute muscles. It will also improve your balance, flexibility and stability.

How To Perform

• Stand with feet close together. Bend forward as you lift the right foot backwards.
• Keep the supporting leg slightly bent. Lower the upper body as low as you can and lift the right leg until it’s aligned with the back.
• Slowly lower the leg as you lift the upper body to return to starting position.
• Finish reps for one leg then switch legs and do the same number of reps.

It may not be possible to perfectly execute this exercise the first time you try it but here’s how a perfect one leg deadlift should look like – the back should be straight, touch the floor with both arms and keep the lifted foot aligned with the hips and the back.

9. Wall Sits

Isometric exercises are also good for the knees because there’s no movement. Use a timer to track duration for each set.

How To Perform

• Stand a step away from the wall then lean backwards and rest your back on the wall.
• Slowly slide downwards until the thighs are parallel to the floor and hold that position as long as you can. Make sure the toes are past the knees when in this position.
• If this is too challenging, do wall slides – place a tennis ball on your back or use a smooth wall.
• Slide downwards until the thighs are parallel to the floor then slide up until you’re upright and repeat.

 10. Step Ups

This a great low-impact exercise for strengthening the quadriceps, hamstrings and glutes. Use a box lower than your knee height.

How To Perform

• Stand a step away from the box then step on the box with one foot.
• Straighten the front foot and place the rear foot on the box. Then lower both feet down and repeat the movement.
• Do this exercise slowly to avoid hurting yourself.

 Worst Leg Exercises For Bad Knees

These exercises can make your knee problem worse. Avoid them completely or do them in low reps.

1. Plyometric Exercises

Avoid any exercise that requires jumping. Plyometric exercises have a high injury risk and they put a lot of strain on the knees. So stay away from box jumps, jumping jacks, frog jumps and so on.

2. Deep Squats

Deep squats are challenging even for folks with healthy knees. They stretch the hamstrings and quadriceps which are attached to the knees. Avoid squatting below parallel until your knees become stronger.

3. One Leg Jump Rope

Jumping rope[ref]Bring It On! The 21-Day Jump Rope Challenge, Focus Fitness[/ref] with one leg puts a lot of pressure on the knees. If you like jumping rope, jump both legs and stick your landing to reduce the impact on the knees.

4. Forward Lunges

Forward lunges may hurt your knees because of the pressure placed on the knees when you make a big stride.

5. Sprinting

Avoid sprinting especially on flat ground or downhill. Hill sprints actually reduce the impact on the knees – give them a try if your knee pain is not severe. You should also know they burn lots of calories.

Final Word

There you have it my friend. These exercises will strengthen your legs and even strengthen your knees.

The best thing is to listen to your body. If you feel uncomfortable when doing an exercise, stop. Try different exercises on this list and choose the ones you’re comfortable with.

Which leg exercises do you do that don’t strain your knees?