The Achilles tendon is extremely important to running, but it’s also easily injured. Here’s how to prevent and treat Achilles pain.

It’s the thickest and strongest tendon in your body, and it’s one of the unique parts that allows humans to run long distances. Unfortunately for runners, it’s also highly vulnerable to injury. The Achilles tendon, which attaches the calf muscles to the heel bone, sustains loads more than twice your bodyweight during running. This heavy workload combined with a limited blood supply makes the Achilles tendon, quite literally, a runner’s Achilles heel.

What Causes It

Achilles tendon pain occurs when the tendon becomes inflamed, either in the middle portion or where it inserts at the heel. When the inflammation is acute, it is considered tendonitis, whereas chronic pain involves degeneration to the tendon and is categorized as tendinosis.

“Achilles tendonitis is a result of either overloaded tissues or fatigued tissues, in that the body is not delivering enough oxygen to the tissues,” says Brent Yamashita, P.T., M.P.T., C.F.M.T., a physical therapist in Steamboat Springs, Colo. Increasing speed, hill work or mileage when your tissues are not prepared for these demands can all put a runner at higher risk, as can faulty running mechanics and muscle imbalances.

Prevention

Once you have Achilles tendon pain, it can take months to heal, so you’re best off taking steps to prevent it, Yamashita says. He recommends that beginning runners vary their training surfaces (asphalt, trails, grass, etc.) and take walk breaks, which help deliver adequate amounts of oxygen to tissues and tendons.

Dynamic stretching of the lower body in general before a run can also help improve blood flow and reduce stiffness, while static stretching of the calf muscles post-run can help restore tissue length. When it comes to strength, Yamashita recommends including single-leg calf raises in your training regimen, aiming to gradually complete at least 50 repetitions on each leg. He also advises looking beyond the muscles in the lower leg by adding trunk stability and upper-body and hip flexibility.

Last but not least, runners looking to improve their speed should aim for a cadence of 180 steps per minute as opposed to increasing their stride length. “Longer strides can lead to higher peak impact forces,” he says. Taking shorter strides with higher cadence can decrease your risk of injury.

Treatment

If you feel any pain around your Achilles tendon, your first line of defense is to rest and ice in order to calm the symptoms. Yamashita recommends “active rest,” which can include biking, swimming, strength training and any other activities you can tolerate. You may also try adding a 5mm heel lift in both shoes to reduce the stretch on the Achilles as you return to pain-free running.

If symptoms don’t resolve on their own after a few months, you’re now considered to have tendinosis, as opposed to tendonitis. Treatment for tendinosis involves remodeling of the injured tissues, often through eccentric loading of the tendon, and may also include modifications to footwear, manual therapy, addressing the nerves that innervate the Achilles tendon and strengthening muscles of the lower body, core and feet. Yamashita recommends seeing a physical therapist who can prescribe treatment specific to your situation.

Try This Exercise

Eccentric Heel Drops

Eccentric heel drops have proven to be one of the most effective exercises for resolving Achilles tendinopathy. Here’s how to do them: