Why Your Knees Hurt When Running — Plus How to Stop the Pain

Every runner fears the day their joints might start to ache, especially if it's knee pain after running since it can keep you from training. But, in truth, your fate isn't sealed: In a study published in Arthritis Care & Research, older folks who had been runners in their youth were not at any greater risk of knee pain later in life than those who never laced up their sneakers. What's more, those who had logged the most miles throughout their life actually had the fewest knee aches, regardless of age.

The secret to preventing knee pain during or after running: You have to protect your joints from the start. "While it is a common fallacy that running is bad for your knees, running is still a repetitive motion, so many injuries stem from muscle imbalances that add up over time," says Ian Sharman, USA Track & Field certified coach and head coach at Sharman Ultra Endurance Coaching.

Below, are some of the most common reasons why you get knee pain after running, plus what to do about it and how to prevent it from getting worse. (More: The Best Free Running Apps for Any Type of Training).

Why You Might Get Knee Pain After Running

IT Band Friction Syndrome (ITBFS)

IT-band issues are one of the most common nuisances that plague runners. ITBFS occurs when the tendon from your hip to your outer knee gets tight and therefore inflamed, irritating the outer knee bone. If your knees hurt while running and you feel tightness on the outside of your knee, ITBFS may be why.

Fix it: Bummer alert: The only way to ease severe ITBFS pain is to completely rest the tendon (AKA stop running), says Leon Popovitz, M.D., founder of the New York Bone and Joint Specialists in New York. Physical therapy may also be needed to ease the inflammation. For mild cases, a foam roller to stretch post-run will quickly become your best friend. (These are the best foam rollers for muscle recovery.)

Tendonitis

If you've recently upped your mileage or have increased your intensity in a short amount of time, the overuse of your knee can cause the tendons surrounding it to become strained and inflamed. This overuse is called tendonitis and can make your morning jogs pretty miserable.

Fix it: Tendonitis issues can typically be resolved with rest, ice, compression, and easing back into your usual routine. Scott Weiss, D.P.T., licensed physical therapist, board-certified athletic trainer, and exercise physiologist also recommends eccentric exercises which focus on lengthening the muscle fibers to gently stretch the tendons and prevent knee pain when running.

Runner's Knee

Similar to ITBFS, runner's knee occurs when cartilage in the kneecap is irritated, causing mild to moderate pain when running. With this condition, your knees hurt when running, when going up and down the stairs, or after prolonged periods of sitting. Contrast that to the feeling of tightness — a sign of ITBFS.

Fix it: Hamstring stretches and leg lifts can help runner's knee, according to Dr. Popovitz. Do these post-run stretches to help your legs get stronger and prevent mid-run aches. (If your knees hurt when running, cannabis pain relief creams might be able to help — but do they really work?)

Meniscus Tear

Your meniscus sits on both the inside and outside of your knees, helping to provide stability and distribute the stress of the weight you put on your joints. One wonky bend or fall can tear the meniscus, which typically results in slight knee swelling (anywhere from immediately to an hour after), and pain when bending your knee.

Fix it: The only way to confirm a meniscus tear is to go see your doctor, who will usually follow up with an MRI. While some outer tears may heal with rest, larger tears may call for surgery.

ACL or MCL Tear

Ligament tears can happen for a number of reasons, such as twisting your knee (say, as you stumble in a divot or pothole during a run), hyperextending your knee, or having to stop suddenly mid-stride. Your ACL (anterior cruciate ligament) is the ligament that connects the thigh bone to the shin bone on the outside of your knee while your MCL (medial collateral ligament) does the same on the inside of your knee.

Fix it: Though rare for the everyday casual runner, if you hear a loud pop, experience sudden or extreme pain, or have difficulty putting any weight on your leg, you may have an ACL or MCL tear and should see a doctor as soon as possible for your best course of action and rehabilitation plan.

Knee Sprain

If you're feeling a little creaky and tender and you have knee pain after running, your knees may be taking more abuse than they can stand. Maybe it was extra miles or a bad fall on that last loop of the track. When this happens, your knee extends past its comfortable point and sprains. (Plus Is It Bad To Workout Every Day?)

Fix it: Get yourself checked out by a doctor, and make sure to rest, ice, and elevate your knees whenever possible. Compression is also important, just don't wrap your knee too tightly, as that could cause more swelling. OTC medications can also help reduce inflammation and pain so you can get back on your feet faster.

What to Do If Your Knees Hurt When Running

If you have knee pain during or after running, try these eight pro tips to heal faster (or prevent knee pain before it starts).

Wear Proper Running Shoes

"The foot is made up of 26 bones, 33 joints, 19 muscles, and 107 ligaments, and these take the brunt of the pounding with each step of the day," explains Pamela Kopfensteiner, D.P.T. at Professional Physical Therapy in New Jersey. You need running shoes that support your natural construction-high arches, pronation, supination-and diffuse the impact shooting up the rest of your leg. Hit your local running store and ask for a gait analysis, which will tell you exactly what support you need, suggests Kopfensteiner.

Running shoes are specifically designed to absorb the shock each time your foot pounds the pavement. But the more you wear them, the more worn down the shock absorption becomes, increasing the forces shooting up your joints — a recipe for knee pain, Kopfensteiner says. (You might also benefit from trying one of the best shoe insoles in your sneakers.)

While it's true that shoes break down over time, it's not clear how many miles or months sends them into the graveyard, Williams adds. Expert opinions range between advising you toss your shoes every 300 miles to every 600 miles — which is a massive difference. "Some runners are tough on their equipment while others are not, but most runners will feel when they need new shoes," he adds. If your knees hurt when running, check out the bottom of your shoe. If the tread is significantly worn, if there are creases in the midsole, or if you can more easily bend the shoe, it's probably time for new kicks.

Strengthen Your Hips and Core

You've probably heard by now that even if you're a runner, you should be strength training (after all, it can take you one step closer to a PR). But there are certain areas to pay special attention to when it comes to preventing knee pain. A study of 400 healthy female runners published in Medicine & Science in Exercise & Sports found that, over two years, women who developed runner's knee had much greater pelvic instability — that is, weakness in their hips — compared to runners who didn't experience knee issues. Meanwhile, a study in the Journal of Athletic Training found that almost 80 percent of aching runners who strength trained with a focus on their hips and core or knees and thighs reported their knees hurt when running significantly less after just three or four weeks of lifting.

Women should focus on hips and core strength most, says D. S. Blaise Williams III, Ph.D., director of VCU RUN LAB at Virginia Commonwealth University. Kopfensteiner agrees: "Running is unique in that there is a 'flight' stage — a point in time when neither foot is on the ground," she explains. "While in midair, it's your core's job to control the rate at which your extremities return to the ground. When the control is increased, the force shooting through your joints when landing decreases and prevents injury to the knee joints."

Strength train once or twice a week. (This beginner strength training guide is a good place to start). Or design-your-own plan with planks, side planks, medicine ball core rotations, clamshells, fire hydrants, and open chain hip abduction. Then move up to plyometric exercises such as jump squats, jumping lunges, and single-leg landings. Once you conquer this, add uphill sprints to your training schedule, adds Williams.

Don't Rush Training

Once signing up for a race, your instinct may be to ramp up your mileage ASAP — but that's actually one of the worst things you can do — especially if your knees hurt when running. "It takes time for the body to adapt to training, and your ligaments and tendons improve slower than the muscles since they get less blood flow," explains Sharman. "Even if your muscles feel ready to take on more and more, it's important to allow enough time for the support around the joints to catch up." A good rule of thumb: Don't increase mileage by more than 10 percent each week. (

Train Off-Road

"Running on trails and hills can increase the variety of movement and build up a more even level of strength and stability through the legs and joints," says Sherman. While there isn't a big difference among pavement, track, gravel, or trails as far as knee torque and impact are concerned, there are variables for how unstable the surface is or how much you need to pay attention (think: roots, curbs, cars), adds Williams. "All of these conditions result in the muscles contracting for stability, which results in shorter, more controlled steps — which is why many runners report more comfortable runs on trails or grass," explains Williams. (Here are the best trail running shoes for women)

Aim to veer onto different terrain at least once a week. (The closer you get to the event, though, the more you should train on that terrain — so pavement for a road race, trails for a trail race, adds Sherman.) The one terrain to stay away from if your knees hurt when running? Sand. "A run on the beach sounds romantic but it results in a huge load on the calf muscles that you may not be ready for," adds Williams, which can impact all of the surrounding joints, too.

Lean Forward

"The way the foot hits the ground when running contributes to forces which impact the knee joint," says Kopfensteiner. Leaning slightly forward while running can decrease these forces. And in fact, research has proven that leaning slightly forward during a run transfers your weight from your knees to your hips, thereby reducing pain. Try it: Flex more at the hip and allow your torso to come forward seven to 10 degrees. (

Increase Your Stride Rate

"Stride rate is likely the most important factor we know of right now that is easily changeable and reduces both acute and cumulative load on the knee," says Williams. Shorter steps that propel you to a faster pace decrease the force the quadriceps place on the knee cap, he explains. And in fact, a small study in the Journal of Orthopedic and Sports Physical Therapy found that when runners go slow, they do decrease the load on their knee per stride, but they actually increase the load over their entire run since every stride adds up. When the study participants ran faster, they reduced the overall stress on their knees by 30 percent compared to their easy pace. There is no single optimal number, but if you are below 160 steps per minute, you should try and increase that by five to 10 percent, says Williams.

And that's way easier to do than it sounds. Try this if your knees hurt when running: Determine your steps per minute by getting on a treadmill and having your friend track how many times your right (or left) foot strikes the ground in 60 seconds. Double that number. If it's above 160, you're in the clear; if it's under, calculate a five percent increase, then turn to Spotify's playlist listed by BPM that matches that goal rate. Your brain and legs will automatically try and match the new cadence, though it'll take about four to six weeks of practice to make it habitual, adds Williams.

Stay in Control Downhill

"The tendency when running downhill is to over-stride or reach out," points out Williams. Remember, you want shorter steps to decrease the force on your knees, so maintain your stride rate when going downhill, he suggests. Plus, it's a quad killer if you launch down the hill too fast —so stay in control.