Gearing up for a mountain or trail run means risking an ankle sprain. When it comes to hill running on trails, uneven footing and misplaced steps are facts of life, and if your stability and mobility is already shaky, it’s only a matter of time before you turn your ankle over and you start searching for methods of how to heal a sprained ankle fast.

Thankfully, a myriad of strength and mobility exercises exist to lower the risk of an ankle sprain, and if you hurt your ankle, there’s a right and wrong way to treat it. We enlisted the help of doctor of physical therapy Robert Gillanders of Bethesda, Maryland, as well as Anne Holly Johnson, a Massachusetts General Hospital ankle orthopedic surgeon and Harvard Medical School instructor, to keep you sure-footed on the course.

Not All Sprains Are Created Equal

Degree of injury affects the answer to how to heal a sprained ankle fast. The most common ankle sprain is an inversion injury, which occurs when the ankle rolls outward in the direction of the pinkie toe. “The ligaments that connect the fibula to the talus [the large bone just below the tibia] that normally stabilize are being stretched and torn,” Holly Johnson says. Inversion sprains are known as low ankle sprains; the opposite is a high ankle sprain, or eversion sprain, during which a stretch or tear occurs to the ligaments that connect the fibula to the tibia. Low ankle sprains are most common, in part because the foot’s natural proprioception (orientation relative to the ground) positions the outside of the foot to touch the ground first.

Physical therapists like Gillanders score the severity of an ankle sprain by grade, an important score when it comes to . “A grade 1 will be a mild sprain where there’s microscopic tearing of the ligaments,” he says. “A grade 2 would have a more significant tear; a grade 3 is completely torn.” If you hear a pop, that could be bone hitting bone. “The foot pitches out to the side and the talus comes crashing toward the fibula, and you can feel it grotesquely clunking within the joint face,” Gillanders says.

Why Ankles Sprain Differently

Not all ankle sprains are created equal; how badly you hurt an ankle depends on how hard the initial impact was, and playing into the answer to how to heal a sprained ankle fast. “If you’re running down stairs and fall down and your ankle turns, you’re doing to do a lot more damage than simply missing the top step,” Holly Johnson says. “If you’re in a Spartan race and you’re running downhill and you jump a log and land on your ankle, you’re going to have a much higher and bigger injury than if you were gingerly stepping.”

A “higher” injury results from a more serious impact; a syndesmosis is a slightly mobile joint that is spanned by connective tissue—like the connection between the fibula and the tibia—and injuring such a joint with a high ankle sprain requires more force than a simple inversion sprain.

The shape of your foot can also influence your chances of a sprain—and don’t assume that a high arch is desirable. “The low arch has gotten a bad name,” Gillanders says, “but a low arch is adaptive to hitting the ground and being able to absorb force in a different way from a high arch.” He notes that because high arches are rather inflexible, they’re more likely to hold their shape and allow the ankle to roll over (a low arch, by comparison, might have more give in an inversion sprain situation).

Want to add more strength training to your workouts? Download the Spartan Bodyweight Training Plan.  

Train to Avoid an Ankle Sprain

If you thought leg day in the gym was unsexy, boy do we have a routine for you—actually, though, it’s important to train all of the muscles relevant to obstacle racing, not just the biggest ones. “Most joints in the body are reliant on active tissues and passive tissues. Active tissues would be muscles; passive tissues would be things like ligaments and joint capsules,” Gillanders says. Protecting the passive tissues means training the active tissues that surround them.

A must for runners is balance, and although it seems redundant, it’s incredibly important to be sure-footed over a 10,000-step race. “I want runners to be able to hold a single-leg balance, eyes closed, for a 30-second count,” Gillanders says. Pro tip: balance in a running stance, with your non-plant foot raised and your thigh perpendicular with the ground. Hold your arms in running position and stand on a squishy surface like a Bosu ball to up the ante.

“Then I look at single-leg squatting; that’s a closed-chain range of motion assessment,” Gillanders says. What he means is he’s isolating the ankle to see whether a patient can move their leg over a fixed plant foot. “If you have ankle stiffness, you’re going to see that being compromised.” He’ll also conduct single-leg heel raises, for which he expects runners to hit 30 repetitions. “Bodyweight plantar flexion is only a third of the stress of running,” Gillanders says. “A lot of middle and long-distance runners roll their eyes with these tests, but you have to show me the ankle will be controlled and stable over a 10-mile course.”

If you’re struggling to balance for 30 seconds with your eyes closed, if you can’t seem to move your knee over your ankle in single-leg squats, if you can’t manage 30 single-leg heel raises—you’ve got work to do. A last tell-tale sign of poor ankle mobility: turning your feet outward during squats. Even if you have a full range of motion, kicking your heels inward is indicative of poor ankle mobility, Gillanders says.

How to Heal a Sprained Ankle Fast

As tempting as it might be to push through a mid-workout or mid-race sprain, it’s important to know when to quit. If the worst happens—a mid-Spartan race sprain—first evaluate the injury on a pain scale. “1, 2, 3 out of 10; you can work through that,” Gillanders says, noting than any more pain is cause to stop. The test for running on a sprain, he says, is whether you can do so without a visible limp. “If you grind through it you’ll create a problem further up the chain,” he says. “When you’re off-road and dealing with these sort of obstacles, you’re not going to be able to do it.”

So how to heal a sprained ankle fast: Once you’re off the course, evaluate whether you can bear weight on the injured ankle. “If you can’t walk or put weight on the foot afterward, you should have an X-ray to make sure there’s no fracture,” Holly Johnson says. “If it turns outward but after a few steps you’re walking on it, get off it and RICE.” That stands for rest, ice, compression, and elevation, and Holly Johnson recommends that routine for at least the first 24 hours following a sprain to help with how to heal a sprained ankle fast. After that, she says, apply compression for a couple of days or weeks as needed, and keep the ankle moving up, down, and side to side to prevent excessive scar tissue formation. Gillanders likes Epsom salts for inflammation that doesn’t go away after a couple days. “The magnesium has a real positive effect on swelling, especially since the ankle is so far away from the heart,” he says. 

A torn ligament will never be the same, and ankle sprains are no exception. “You can stretch a rubber band hundreds of times and it’s not going to be damaged, but if you overstretch it multiple times, it becomes more papery than elastic. If you pull it so hard it actually breaks, you can put some tape on it, but it loses elasticity,” Holly Johnson says. “If ligaments tear and bond back together with scar tissue, you can either end up with a tight, scarred ankle, or you can end up with a looser ankle.”

Apart from the conscious mental burden of re-injuring an ankle that’s been sprained, the brain readapts to the hurt ligament. “Ligaments have a reflex arc; there are actually nerves in the ankle that detect uneven ground in the ligament area,” Holly Johnson says. She explains that the nerves in the foot sense unstable ground, send that message to the brain, and the brain tells the ankle to stabilize itself. That process, Holly Johnson says, is disrupted with an ankle sprain. “You may have a few ankle sprains and the ankle still feels tight,” she says. “You’re unstable because you don’t have a normal reflex arc; part of the recovery process is reestablishing a normal reflex arc.”

How to heal a sprained ankle fast? It varies. As a physical therapist who treats all types of sports injuries, Gillanders notes that it’s tough to generalize a treatment plan that works for everyone. If you know you’re hurt, see a PT sooner rather than later. “What I see in the clinic most commonly is someone who guts through an injury, and eventually it catches up with them,” he says. “People get dinged up down the road because they didn’t fully resolve the issue.”

Want to get on the road to the mountaintop? Download The Mountain Series Training Plan as your blueprint. #noexcuses