Many of my clients have various knee problems, and I’ve been getting a lot of questions regarding cardio in these situations. Today, I came across an article on Yahoo Health that addresses this issue pretty well. Hope it answers some of your questions for you!

Make over your cardio workout so it’s easy on the knees

by Sarah McColl

Sometime in the past several weeks, either while while running at the gym, skiing on a frozen lake, or just walking weirdly, I managed to hurt my knee. Not being able to exercise in the usual ways has been devastating, but it turns out that female athletes are between two and eight times more likely to injure their ACL knee ligaments than men.

Studies have found that hormones associated with a women’s menstrual cycle may affect the laxity of the knee joint. For those as addicted to the mood-boosting effects of exercise as I am, here are some ways to exercise that aren’t as tough on the knees as pounding the pavement.

Stationary bikes

Even though you’re not going anywhere, there’s something transporting about riding a stationary bike. You can put on your favorite music, close your eyes, and just pedal in time to the music. Make sure your seat is high enough so that your knees are not bent beyond a 90-degree angle, and your knee should be slightly bent when your leg is fully extended in the down-stroke.  An upright stationary bike (as opposed to the kicked back recumbent bike) gives you a higher intensity workout.

Boxing

This idea comes courtesy of my girl Jillian Michaels. And by “my girl,” I mean she regularly kicks my butt in the living room via her workout DVDs. Just jabbing rapidly or shadow boxing while standing (or even perched on the edge of a chair) will get your heart rate up.

Elliptical trainer

Working out on an elliptical trainer Is as low-impact as walking but can provide more intense cardio. For those who really love to run but who can’t stand the impact on the joints (up to 3x your body weight with each step!), the elliptical machine can get close to scratching that runner’s itch. Ideally, choose a machine that gets your arms pumping in a push-pull action to get a full-body workout.

Ergometers

Ergometers are like stationary bikes, except instead of pedaling with your legs, your arms to do the work. Most gyms have at least one, and it’s a godsend for someone who can’t be on their feet at all but still wants to workout.

Swimming

Have you ever noticed how pro swimmers have some of the most miraculous bodies out there? The reason, in part, is that the water’s resistance makes your muscles work harder to perform movements than if they were traveling through air. Meanwhile, the buoyancy of water supports your entire body weight, making swimming a no-impact exercise. Here are 50 easy to moderate swimming workouts.

To protect your knees against injury, exercises like knee circles, wall sits, hamstring curls, and leg lifts can help strengthen the muscles that support the knees.