An ankle sprain is the classic trail running injury: a loose rock, a root, a misplaced foot on a descent, and your ankle rolls outward. Treated properly, the vast majority heal well. Poorly rehabbed, they tend to come back. Here’s how to recognize a sprain, treat it, get back to the trails without rushing things and, above all, avoid it in the first place.
The short answer
- The biggest risk factor for an ankle sprain is a previous sprain: rehab matters just as much as healing.
- If you can’t take 4 steps, or if a specific bone in your ankle or foot hurts when pressed, see a doctor to rule out a fracture.
- The recommended treatment is functional: brief protection, early weight-bearing and exercises, rather than long immobilization.
- A balance and proprioception program lasting a few weeks clearly reduces the risk of spraining it again.
- For prevention: balance work, strength training, downhill technique, shoes suited to the terrain, and an ankle brace if you’ve sprained it before.
Contents
- Why ankle sprains are the trail runner’s injury
- Sprain or fracture: when should you see a doctor?
- What to do on the spot, mid-run or mid-race
- How to treat an ankle sprain
- Proprioception rehab: the step you can’t skip
- Getting back to trail running after a sprain
- How to prevent ankle sprains in trail running
- FAQ: ankle sprains in trail running
Why ankle sprains are the trail runner’s injury
Most of the time it’s a lateral sprain: your foot rolls inward and the ligaments on the outside of the ankle get stretched, or even partly torn. The ligament most often affected connects the lateral malleolus (the bony bump on the outside of your ankle) to the talus, just in front of it.
Ankle sprains are among the most common sports injuries, especially in activities with lots of changes of direction and footing (Doherty et al., 2014). Trail running stacks up the risky situations: uneven ground, rocks and roots, fast descents, fatigue that builds over the hours, night running by headlamp. Unlike most road running injuries, it isn’t an overuse injury but a trauma: it happens in a split second.
The best-established risk factor is a previous sprain (Vuurberg et al., 2018). After a first sprain, the ankle loses some of its balance and reaction ability, which leaves it open to further incidents. That’s why rehab is at least as important as letting the ligament heal.
Sprain or fracture: when should you see a doctor?
A sprain shows up as pain on the outside of the ankle, swelling and sometimes bruising within the following hours. A crack or pop at the moment of injury can be alarming, but on its own it doesn’t tell you how serious it is.
Doctors use a set of simple criteria, the “Ottawa ankle rules”, to decide whether an X-ray is needed. They’re very reliable for ruling out a fracture (Bachmann et al., 2003). In practice, get checked out quickly if:
- you can’t take 4 steps putting weight on the ankle, either right after the injury or later on;
- pressing on the back edge or the tip of either ankle bone (malleolus) hurts;
- pressing on the base of the 5th metatarsal (the bony bump halfway along the outer edge of your foot) or on the navicular bone (halfway along the inner edge) hurts.
Even without these signs, seeing a doctor or physio a few days after the sprain lets you assess how serious it is and tailor your rehab. That’s all the more useful if this isn’t your first sprain.
What to do on the spot, mid-run or mid-race
Stop, then test whether you can bear weight by walking a few steps on flat ground. If you can’t put weight on it or the ankle gives way, don’t push it: rolling an already injured ankle a second time makes the damage worse. Let the race organization or your running partners know, and walk to the nearest access point, using your poles if you have them.
If you can walk, wrapping it with an elastic bandage or tape can support the ankle until you get back. Carrying on with a long race on a sprained ankle is rarely a good idea, especially if there are technical descents still to come. In ultras, the medical stations can help you assess the situation: don’t hesitate to stop there.
How to treat an ankle sprain
Current guidelines favor “functional” treatment: a short period of protection, then getting weight back on the ankle early and doing exercises, rather than a long stint in a cast (Vuurberg et al., 2018). Depending on the severity, your doctor or physio may suggest an ankle brace or splint for a few weeks.
For the first few days, protect the ankle, keep it elevated and walk as soon as the pain allows. Ice and painkillers can help, but talk to your doctor before taking anti-inflammatories: their benefit for healing is debated. Our article on how to manage a running injury covers these first steps in detail, along with how to stay active without making the injury worse.
While the ankle heals, you can maintain your fitness with cycling, swimming or aqua jogging as long as they don’t trigger pain. Keep up your upper-body strength work and core training too: there’s no need to stop everything.
Proprioception rehab: the step you can’t skip
Lots of trail runners start running again as soon as the pain is gone. That’s exactly where the trap closes. In a cohort followed for a year after a first sprain, a large share of participants developed chronic ankle instability, with the ankle feeling like it gives way and repeated sprains. The people who struggled most with balance and jumping in the weeks after the sprain were the most at risk (Doherty et al., 2016).
The good news is that this deficit can be trained. In a randomized trial, athletes who had sprained an ankle followed an unsupervised 8-week home balance program: their risk of another sprain within the year dropped sharply compared with the group that only received usual care (Hupperets et al., 2009). A systematic review confirms that balance training reduces the risk of recurrence in people who have already had a sprain (McKeon and Hertel, 2008).
Sample progression, 3 times a week
Start once putting weight on it is pain-free, ideally with your physio’s go-ahead, and only move up to the next step once you can do the current exercise with good control and no pain.
- Static balance: stand on the injured leg for 30 seconds, then do it with your eyes closed.
- Unstable balance: same exercise on a cushion, a balance board or a folded mat, then while moving your arms or throwing a ball.
- Strengthening: single-leg calf raises, and eversion against a resistance band (turning your foot outward) to strengthen the muscles that protect the ankle.
- Hops: small single-leg hops on the spot, then sideways and forward hops with a controlled landing.
- Trail-specific: walking, then easy running on uneven ground, going up and down steps, small hops between markers on the ground.
Keep this work going for several weeks after you’re back running, even when everything feels fine: that’s when the risk of spraining it again is highest. To ease back in with a plan that builds your load gradually and includes strength sessions, you can try RunMotion Coach free for 7 days.
Getting back to trail running after a sprain
How long it takes depends on the severity: a few days to a few weeks for a mild sprain, longer for a severe one. Rather than going by a date, rely on concrete markers. You can start running again when you walk without pain, you can balance on the injured leg as well as on the other one, and you can hop on the spot on that leg without pain.
Start on flat, even ground, road or smooth paths, then gradually bring back easy trails, climbs and finally technical descents, which put the most stress on the ankle. Our return-to-running programs give you a concrete progression for the first few weeks.
For the first few months, an ankle brace or tape on technical runs is a sensible precaution: guidelines list them as effective at limiting repeat sprains (Vuurberg et al., 2018). They don’t replace rehab, they complement it.
How to prevent ankle sprains in trail running
Train balance and strength all year round
Proprioception exercises aren’t just for rehab. A few minutes two or three times a week, built into your strength and conditioning for trail running, keeps sharp the reflexes that save you from a bad landing. It matters even more if you’ve sprained an ankle before.
Work on your downhill technique
Descents are when your ankle is most exposed. Look 3 to 5 meters ahead to plan your foot placement, take short, quick steps, keep your arms out for balance and avoid leaning back. Our tips on how to run downhill on trails go through the technique and how to train it.
Choose shoes suited to the terrain
On technical terrain, a shoe with good grip, a secure foothold and a not-too-high stack helps keep your footing stable. Don’t try out a new pair for the first time on race day. Our roundups of the best short-distance trail running shoes and long-distance trail running shoes help you choose based on your terrain and distance.
Manage fatigue and stay alert
As you tire, your focus and the quality of your footing drop. On long runs, slow down on technical sections, eat and drink regularly to stay sharp, and use a powerful headlamp at night. Poles can also give you extra support on steep descents.
Get your ankles used to the terrain gradually
If you’re coming from road running, gradually increase the share of technical trails in your training rather than jumping straight into a very rough, rocky race. A trail running training plan tailored to your race helps you pace that progression. To go further, check out all our tips to prevent running injuries.
FAQ: ankle sprains in trail running
How long does it take to get back to trail running after an ankle sprain?
It depends on how bad it is: a few days to a few weeks for a mild sprain, longer for a severe one. Start running again when you can walk without pain, your balance on the injured leg is back and you can hop on it without pain.
Can you run with a sprained ankle?
Not in the first few days. As long as putting weight on the injured leg or hopping on it hurts, stick to cycling, swimming and your rehab exercises. Then restart on flat ground before heading back to the trails.
Should you wear an ankle brace for trail running?
After a sprain, a brace or tape on technical runs helps limit repeat sprains for the first few months. It complements balance and proprioception rehab, it doesn’t replace it.
Do you need an X-ray after an ankle sprain?
Not always. An X-ray is recommended if you can’t take 4 steps or if specific bones in the ankle or foot hurt when pressed. If in doubt, see a doctor.
A well-rehabbed sprain is rarely serious, but a neglected one often comes back. Take the time for proprioception work, return gradually, then keep a few minutes of balance work in your routine. To prepare for your next trail race with a plan that includes strength work and adapts your training load, try RunMotion Coach free for 7 days.
Updated on 30 October 2026. This advice doesn’t replace the opinion of a health professional: if in doubt, see one.
Sources: Vuurberg et al., Br J Sports Med, 2018 · Doherty et al., Sports Med, 2014 · Bachmann et al., BMJ, 2003 · Doherty et al., Am J Sports Med, 2016 · Hupperets et al., BMJ, 2009 · McKeon and Hertel, J Athl Train, 2008.
