When you are suffering from knee pain, you may feel forced to take a step back from exercise.
Considering that every step you take places a force on the knees of 1.5 times your body weight—and more on an incline—even low-intensity exercise can be painful.
But it can be difficult to get back into an exercise routine when you’re feeling pain. That’s why we’re looking at the best cardio exercises for bad knees.
These are exercises you can do to safely strengthen both the muscles and the cardiovascular system.
What are common knee pain causes?
Knee pain can have a number of causes. Most knee pain is a result of either a traumatic injury or overuse of the joint.
Overuse injuries occur there is an overload of pressure on the knee joint, especially when it’s not fully recovered from earlier exercise. This can happen from running long distances—the repetitive force on the knee upon the foot strike—or from an overload of exercises involving the knee, such as squats, lunges, etc.
Traumatic injuries can happen at any time while playing sport and include things like sudden changes of direction that force the knee the wrong way, or being hit on the knee. If the knee moves the wrong way, it could result in torn cartilage or a torn ACL—anterior cruciate ligament.
Traumatic injuries can also include things like vehicle accidents and falls. These are more serious than overuse injuries as there may be other underlying problems caused by the blow.
Arthritis is another common cause of knee pain. Osteoarthritis occurs in 10 percent of males and 13 percent of females—over 60 years old—in the USA. However, it’s becoming more common amongst younger people, and the knee is the most common joint affected.
What parts of the knee can be affected?
Depending on the cause of the knee pain, a number of different parts of the knee could be affected. The knee is made up of bones, the joint, muscles, tendons, and ligaments. Any one of those could be affected by knee pain.
The bones include the tibia, fibula, patella—kneecap—and femur. Muscles include the calf muscles, the quads, and the hamstrings. Then there are the many ligaments and tendons in the knee.
This is why knee pain can be so different from person to person. Where someone feels the pain will depend on how and where they injured their knee.
General warmup and cooldown
Before doing any form of cardio, make sure to warm up properly. Neglecting to warm up could cause further injury to the knee, or an injury to another part of the body.
You can do 5 minutes on a cardio machine or do something more simple like high knees or jumping jacks for 5 minutes. Once you’ve woken up and the blood is flowing, you’ll want to stretch the lower limbs’ muscles before you exercise.
When it comes to cooling down, it’s basically the same process.
Cardio exercises for bad knees
When considering the best cardio exercises for bad knees, make sure to choose low-impact exercise to relieve pressure on the knee joints.
Swimming is widely regarded as the best cardio exercise for the knees as it’s extremely low-impact.
Water provides resistance which is good for building muscle endurance and can also get your heart rate up, improving cardiovascular endurance.
Depending on your ability, choose a distance of 100 to 400 meters. Try to swim your chosen distance four times, with a rest of one to two minutes in between.
Walk or water run in the pool/underwater treadmills
If you don’t enjoy swimming, you can just walk in the pool. It still provides good resistance which can help burn calories and get a good cardiovascular workout. It’s advisable to wear a buoyancy belt while doing this exercise, just to be safe.
Walk in the shallow end of the pool. The water should be between waist and chin height—depending on your preference—but your feet should still be able to touch the floor. Try to walk for 20 to 60 minutes in order to get an effective workout.
You can also do a variety of exercises in the pool that can build strength and improve the range of motion in the knee.
These include things like underwater jump rope with a pool noodle, underwater jumping jacks, and leg pushdowns with a pool noodle.
Water aerobics are considered to be a high-intensity workout in a low-impact environment.
Join a class and take part in a group aerobics session, or simply do it alone at home. It’s often performed to music to provide motivation and keep the intensity up.
Many different exercises are performed in a water aerobics session. They’re done at a fast pace and are designed to improve cardiovascular capacity and muscle strength.
A water aerobics class usually runs from 20 to 40 minutes with short breaks between songs.
If you prefer your cardio to be land-based, walking is low-impact enough to be safe and healthy for joints including the knees.
Make sure you’re wearing the right shoes for walking. If your foot is neutral, you can wear a neutral shoe. But if your foot rolls inwards while walking—overpronation—then you should be wearing a stability shoe. Make sure there is adequate arch support as well.
Even though walking is low-impact, stretching first can help to prevent injury. You want to keep your speed brisk to get the most benefit out of the workout. Beginners should walk for as long as they can at a brisk pace.
Work your way up to 30 minutes. Once you’re used to it, you can walk for up to 90 minutes, taking breaks when you feel the need. Don’t forget to stay hydrated.
Home cardio workout
We’ve put together a home cardio workout for individuals with bad knees who want to improve their fitness and strengthen their knees.
It consists of two sections—a home fitness workout and a machine workout—so you can find what works for you depending on the equipment that you have.
For the home fitness exercises, you will need a resistance band, a medicine ball between four and 10 pounds in weight, and an exercise ball.
Home Fitness Workout
Stand in front of a small raised surface like a box, a bench, or a step. Your feet should be about shoulder-width apart and your back should be straight.
Place one foot on the raised surface and drive through the heel to lift yourself up., tightening the glutes and flexing the hamstrings.
You can either lift your knee like a knee-up—for a full range of motion—or simply tap the surface next to your other foot and lower it down again.
Do this in HIIT-style for 30 to 60 seconds. Then, switch to your other foot and do 3 to 5 sets in total.
2. Partial squats
Squats are hard on the knees but it’s possible to do partial squats to reap some of the benefits. They help to build muscle and strength without aggravating the joints.
Stand with your feet shoulder-width apart and toes facing ahead of you. Tense your abs to stabilize yourself as you drive your glutes backward as though you were about to sit in a chair.
Lower yourself down at the same time, keeping your knees behind the line of your toes.
Lift yourself back up before your knees reach a 90-degree bend. Do 30 to 120 seconds, for 3 to 5 sets.
3. March with an exercise ball
Hold the exercise ball about your head. This is your starting position. Then, bring the ball down and bring the right knee up to meet it. You won’t really “meet” the ball, but the motion is important.
Then do the same with the left leg. Repeat this for 30 to 60 seconds, 3 to 5 sets, alternating legs.
4. Step backs with an exercise ball on front rack position
Pick up the exercise ball and hold it against your chest. Step backward and lower into a half-lunge position. Make sure your knees are not at right angles—the knee angle should be more than 90 degrees.
Using your glute, hamstring, and quad, come back to the starting position. Then, step backward with the other foot. Continue for 30 to 120 seconds, depending on your fitness level, and do 3 to 5 sets.
5. Easy or step burpee
Begin by standing with your feet shoulder-width apart. Your back should be straight. You’ll want to place your hands on the ground, so you can either hinge at the waist to do so or lower yourself into a partial squat and then do so.
Then, step each leg back gently until you’re in a pushup position. Keep your core activated by pulling the navel in towards the spine. When you have held that as long as possible, return to the starting point by stepping forward and standing up.
Do 30 to 120 seconds of this for 3 to 5 sets.
Exercise machine cardio workouts
Try to spend between 20 and 60 minutes on a cardio machine, depending on their fitness level. If you’re a beginner, you may need to work up to 20 minutes.
Rather than running on the treadmill, take a relaxed but brisk walk instead. You may be surprised at how effective walking can be, and it’s also significantly more low-impact than running.
Walking at 3.5 miles per hour for 30 minutes can burn between 107 and 159 calories! As long as you get your heart rate up.
The rowing machine
The rowing machine may appear to work the legs quite a lot, but although it does involve the legs, it’s actually very easy on the knees.
If you’re looking for the most effective cardio workout that won’t hurt your knees, rowing would be it. It’s known to be a muscle-building and cardiovascular workout, and when done with proper form it can increase your fitness immensely.
Although you do use your lower body, much of the motion comes from the core and arms. The knees are relatively safe, and you’ll be getting a low-impact workout that’s extremely effective.
The elliptical mimics the motion of walking, but your foot never leaves the pedal. That means there’s no impact at all!
You can use the elliptical as a full-body workout that works the same muscles as running but with no impact.