Running can be great for your heart—but hard on your knees. Experts agree that as many as 70 percent of runners will become injured at some point, and the majority of those injuries will involve the knees. But knee pain and injuries aren't forgone conclusions, says Kevin Plancher, MD, a leading sports orthopedist in the New York metropolitan area.
The most common running-related knee injuries are patello-femoral pain, also known chondromalacia of the patella or runner's knee, and iliotibial band (ITB) syndrome. Runner's knee is created when the kneecap (patella) rubs against the bottom of the thighbone, and can result in irritation and erosion of the cartilage. ITB syndrome involves irritation to the band of tissue that runs along the outside of the thigh, which can become irritated from repetitive rubbing over the outside of the knee.
Both can be painful and can leave a runner sidelined for weeks or longer, Dr. Plancher said in a statement. "But just because you're a runner doesn't mean you'll have runner's knee or any other knee injury. These problems are typically caused overuse or by a misalignment of the joint that's exacerbated by improper running habits—all things that can be avoided."
Here is some advice for runners who'd rather skip the knee injuries:
• Before you take one running step, be sure you're using the best shoes for your feet. "Everybody's feet and legs are different," says Dr. Plancher, "and every shoe model is unique." Shoes vary widely from manufacturer to manufacturer, and can also change year to year, meaning even if you've been running in the same brand since high school, you need to reassess your shoes every time you buy a new pair (which should be after about 300 miles of wear, or as soon as the soles start to show signs of breakdown). Consulting a trained professional for the right shoe fit for you will help protect your knees. Buying shoes with the right combination of cushioning and stability, which is the shoe's ability to correct any irregularities in your stride, such as your ankles rolling too far to one side is key to injury prevention.
• Train smart: Overtraining—running too many miles without adequate rest between runs or trying to increase your distance or speed too quickly—can hurt your knees. Be sure to incorporate one or two days of rest each week, and mix a few "easy" (or short) runs in with the "hard" (or long) ones. Don't increase your mileage by more than 10 percent a week. Start at a slow pace and be sure to stretch before and afterwards, to keep your muscles limber and your joints flexible.
• Build strength: Keeping your knees healthy also demands some strength training, says Dr. Plancher. Many runners do only one thing—run—instead of cross training. That means they'll strengthen just their running muscles, and they'll do it only by running. Quite often, runners are out of balance when it comes to leg strength, with hamstrings (the muscles that run up the back of the leg, from the knee to the buttocks) that are much stronger than quadriceps (the muscles on the front of the thigh). The result: pain and injury. A smarter strategy is to incorporate regular lower extremity strengthening workouts and core strengthening workouts into your routine, making sure to work on the big muscles (quads and hamstrings) as well as the smaller ones, such as hip flexors, adductors and abductors, which attach to the hips and help move your legs forward and to the sides.
• Supplement wisely: Your knees, like the other joints in your body, need the right amounts of certain nutrients to stay strong and injury-free. Calcium is essential and is used in the body for several functions, including building and maintaining healthy bones. Experts recommend that adults get 1,000 to 1,200 mg (milligrams) each day. Food is the best source of calcium (its plentiful in dark green vegetables and dairy products), but most Americans can use calcium supplements, as well.
Some runners, especially those who have had cartilage damage or knee pain caused by osteoarthritis, also take supplemental glucosamine and chondroitin sulfate, which are natural substances found in and around the cells of cartilage. Glucosamine is an amino sugar that seems to play a role in cartilage formation and repair, and chondroitin is a complex carbohydrate that helps cartilage retain water and maintain its elasticity. They won't help everyone, says Dr. Plancher, but they might help stave off cartilage damage, and research shows that a combination of the two can provide relief for people with moderate-to-severe osteoarthritis pain. The recommended dosages are 1,500 mg per day of glucosamine and 1,200 mg a day of chondroitin sulfate.