Icy Paths and Trail Miles: Balance Training and Ankle Sprains

For most of the year, triathletes run on predictable surfaces: roads, paths and the occasional track. Winter changes that. Many athletes move onto trails for softer ground and variety, the paths are muddy or icy, and early-morning or after-work runs happen in the dark, where a kerb or pothole appears without warning. All of that makes a rolled ankle more likely.

An ankle sprain can feel minor, but it rarely stays minor if it keeps happening. This article covers why ankle sprains recur, what balance training is, what the trials show about preventing sprains, who benefits most, and how a triathlete can fit it into winter training. It isn't a rehabilitation guide for an acute sprain; the safety notes cover when to get one assessed.

Why ankle sprains matter

Most ankle sprains are lateral sprains: the foot rolls inwards and the ligaments on the outside of the ankle are stretched or torn. A 2016 evidence review for the International Ankle Consortium consensus statement, by Gribble and colleagues in the British Journal of Sports Medicine, summarised the picture:

• Lateral ankle sprains are the most common musculoskeletal injury in physically active people, and common in the general population.
• Recurrence is high. Many people who sprain an ankle go on to sprain it again.
• A large share develop chronic ankle instability: repeated giving way, a feeling of looseness, and ongoing symptoms.
• Chronic instability is linked to reduced physical activity, lower quality of life and a higher risk of osteoarthritis in the ankle later in life.

The authors argued that the combined long-term costs of ankle sprains are larger than many people realise. For a triathlete, an ankle that gives way on a trail or a kerb isn't just a missed week; it can become a recurring problem.

What balance training is

Balance training, often called proprioceptive or neuromuscular training, aims to improve your ability to sense and control the position of your ankle. The thinking behind it is that a sprain can leave more than a stretched ligament: joint-position sense and the muscles' protective reactions may also be affected, and balance training aims to restore them. The trials below test the outcome that matters, fewer sprains, rather than these mechanisms.

Typical exercises include:

• Single-leg standing, progressing from a firm floor to a cushion or wobble board.
• Single-leg standing with eyes closed, which removes visual help.
• Single-leg reaches and small knee bends while balancing.
• Hops and landings onto one leg, in later stages.

The programmes in the trials below used simple equipment and short sessions, and some were done entirely at home.

What the trials show

A meta-analysis of seven trials

The clearest summary is a 2015 systematic review and meta-analysis by Schiftan, Ross and Hahne in the Journal of Science and Medicine in Sport. It pooled 7 randomised controlled trials with 3,726 participants from sporting populations.

• Overall, balance training reduced the rate of ankle sprains, with a risk ratio of 0.65. That's about a third fewer sprains.
• In people with a previous sprain, the risk ratio was 0.64, a clear and statistically significant reduction.
• In people without a previous sprain, the risk ratio was 0.57, but this pooled result came from two trials that were each non-significant, and the confidence interval was wide.

The authors concluded that balance training is effective at reducing ankle sprains in sporting participants, particularly those with a previous sprain, and that the evidence for primary prevention, in people who've never sprained an ankle, remains inconclusive.

A home programme after a recent sprain

The most relevant single trial for an age-group athlete is a 2009 study by Hupperets, Verhagen and van Mechelen in the BMJ. It randomised 522 athletes aged 12 to 70 who had sprained an ankle in the previous two months: 256 in the intervention group (120 women, 136 men) and 266 controls (128 women, 138 men).

• Both groups received their usual care.
• The intervention group also did an 8-week unsupervised home balance programme.
• Follow-up lasted a year.

Results:

• Repeat sprains happened in 22% of the intervention group and 33% of the controls.
• That's a relative risk of 0.63, a 35% reduction.
• Sprains causing time lost from sport and sprains with healthcare or productivity costs were also reduced.
• About 9 athletes needed to complete the programme to prevent one repeat sprain.

There was one important nuance. The benefit was significant in athletes whose original sprain hadn't been medically treated; among those who had seen a clinician, there was no significant difference between groups. Inference: for the many athletes who sprain an ankle and never get it looked at, a home balance programme seems to fill some of the gap that structured rehabilitation would otherwise cover.

High-school team sports

A 2006 cluster-randomised trial by McGuine and Keene in the American Journal of Sports Medicine tested a balance programme in 765 high-school soccer and basketball players (523 girls, 242 boys) from 55 teams.

• Sprains occurred in 6.1% of the balance-training group and 9.9% of controls, a significant difference.
• Athletes with a previous sprain had about twice the risk of spraining again.
• Among athletes with no previous sprain, the difference (4.3% versus 7.7%) wasn't statistically significant.

The pattern matches the meta-analysis: clear benefit overall, driven largely by people who've sprained before.

Bracing and other options

Balance training isn't the only tool. A 2017 overview by Doherty and colleagues in the British Journal of Sports Medicine pulled together 46 systematic reviews on treating and preventing ankle sprains.

For preventing recurrent sprains:

• Bracing had strong evidence.
• Neuromuscular training, which includes balance training, had moderate evidence.
• Exercise therapy and bracing were both supported.

A 2018 clinical guideline by Vuurberg and colleagues, also in the British Journal of Sports Medicine, likewise recommended considering braces for preventing recurrent sprains and preferred supervised exercise-based programmes over passive treatments after a sprain.

Inference for runners: a brace is a sensible option on technical winter trails if you've had repeated sprains, while balance training builds the underlying control. They aren't mutually exclusive.

Who was studied

The populations matter here:

• Team sports dominate. The trials are mostly football, basketball and volleyball players, sports with jumping, cutting and contact. Running on uneven ground is a different mechanism.
• Young athletes feature heavily, including high-school players.
• The home-programme trial had a broad age range, 12 to 70, and a near-even sex split, which makes it the closest to age-group triathletes.
• No trial has tested balance training in runners or triathletes for sprain prevention.

Inference: the mechanism, better control of a rolling ankle, should apply to running on uneven or slippery ground, but the size of the effect in runners is unknown.

How common are sprains in trail runners?

A 2021 systematic review by Viljoen and colleagues in Sports Medicine looked at injury and illness in trail runners across 16 studies with 8,644 participants. Most studies were of single-day races, and only three looked at training.

• The foot was the most common injury location, followed by the knee, lower leg, thigh and ankle.
• Skin injuries, such as cuts, grazes and blisters, were the most common type, followed by muscle strains, cramps and ligament sprains.
• Injury rates varied enormously between studies, from 1.6 to 4,285 injuries per 1000 hours, which shows how inconsistently they were measured.

So ankle sprains are a real but not dominant trail-running injury. Inference: for a triathlete adding some winter trail running, a previous sprain is a much stronger reason to start balance training than the trails themselves.

After a new sprain

Balance training belongs in prevention and the later stages of recovery, not the first painful days. The two guidelines above set out what the earlier stages look like.

The Doherty overview found:

• Strong evidence that early mobilisation and anti-inflammatory painkillers (NSAIDs) help pain, swelling and function after an acute sprain.
• Moderate evidence for exercise and manual therapy.
• Conflicting evidence for surgery and acupuncture, and insufficient evidence for ultrasound.

The Vuurberg guideline added several practical points:

• The severity of ligament damage is most reliably judged by a physical examination 4 to 5 days after the injury, once the initial pain and swelling have settled.
• A short period of immobilisation may help pain and swelling.
• For a ruptured ligament, tape or a brace combined with an exercise programme gave the best results.
• Supervised, exercise-based rehabilitation is preferred over passive treatments.
• NSAIDs should be used with caution, because they may suppress natural healing.

The two sources lean in slightly different directions on painkillers, which is one reason to discuss them with a clinician or pharmacist. Inference: for a triathlete, a sprain is also a chance to keep fitness on the bike and in the pool while the ankle recovers, as long as pedalling and kicking are comfortable.

What a third fewer sprains means

Relative numbers can sound bigger or smaller than they are. In the home-programme trial, about one in three athletes in the control group sprained again within a year, and about one in five in the balance group. Inference: if you've sprained an ankle before and run regularly on uneven ground, that's a meaningful difference for a few minutes' work a few times a week. If you've never sprained an ankle, your baseline risk is lower and the evidence for benefit is weaker, so the case is less compelling, though the cost is still low.

Fitting it into a triathlete's winter

The following is inference from the trials, not a tested programme for triathletes:

• If you've sprained an ankle before, especially if it was never assessed or rehabilitated, add balance work. The evidence is clearest for you.
• Keep it short and frequent. A few minutes of single-leg balance work several times a week fits into a warm-up, a strength session or brushing your teeth.
• Progress gradually: firm floor, then eyes closed, then a cushion or wobble board, then small hops and landings.
• Run the course of a programme. The home trial lasted 8 weeks, and the effects were measured over a year.
• Pair it with strength work. TriForward's "Calf and Achilles Capacity" covers calf loading, and "The Ten-Minute Morning Mobility Routine" covers fitting short routines into the day.
• Use a brace on technical trails if you've had repeated sprains.

On the run itself:

• Slow down on ice and in the dark, and choose lit, familiar routes for faster sessions.
• Use a head torch that lights the ground ahead, not just your feet.
• Wear shoes with grip suited to mud or ice, and consider traction devices on snow and ice.
• Keep hard sessions on predictable surfaces. Trails are best for easy running.

A triathlon scenario

The following example is illustrative, not drawn from a study. A 47-year-old triathlete rolled her right ankle on a trail two winters ago. It swelled for a week, she didn't see anyone, and she's turned it twice since, once on a kerb in the dark. This winter she plans two easy trail runs a week to break up road mileage.

An evidence-informed plan might be:

• Balance training first. Single-leg balance on each side, a few minutes, four or five days a week, progressing over 8 weeks to eyes closed and a cushion, then small hops.
• A brace on the trails for the first months, since she has had repeated sprains.
• Easy pace on trails, with intervals kept on the road or treadmill.
• Assessment if it gives way again. Repeated episodes suggest chronic ankle instability, which needs a physiotherapist rather than a home programme alone.

Her history puts her in exactly the group that benefited in the trials: people with a previous, often untreated, sprain.

Common mistakes

• Ignoring a "minor" sprain and never rehabilitating it.
• Starting balance work on a painful, swollen ankle in the first days after a new sprain.
• Stopping after a couple of weeks because it feels easy.
• Doing intervals on icy or unlit trails.
• Expecting balance training to prevent all ankle injuries in someone who has never sprained an ankle; the evidence there is inconclusive.
• Relying only on a brace without building control and strength.
• Running through repeated giving way instead of getting assessed.

What we don't know

• Whether balance training prevents sprains in runners or triathletes. No trial has tested it.
• The best dose. Trials used different programmes, durations and progressions.
• Primary prevention. For people without a previous sprain, the evidence is inconclusive.
• Running-specific risk. There's little data on sprain rates on winter trails, icy roads or in the dark.
• Whether braces affect running economy or comfort over long trail runs.

References

• Schiftan GS, Ross LA, Hahne AJ. The effectiveness of proprioceptive training in preventing ankle sprains in sporting populations: a systematic review and meta-analysis. Journal of Science and Medicine in Sport, 2015;18(3):238–244. doi:10.1016/j.jsams.2014.04.005
• Hupperets MDW, Verhagen EALM, van Mechelen W. Effect of unsupervised home based proprioceptive training on recurrences of ankle sprain: randomised controlled trial. BMJ, 2009;339:b2684. doi:10.1136/bmj.b2684
• McGuine TA, Keene JS. The effect of a balance training program on the risk of ankle sprains in high school athletes. American Journal of Sports Medicine, 2006;34(7):1103–1111. doi:10.1177/0363546505284191
• Doherty C, Bleakley C, Delahunt E, Holden S. Treatment and prevention of acute and recurrent ankle sprain: an overview of systematic reviews with meta-analysis. British Journal of Sports Medicine, 2017;51(2):113–125. doi:10.1136/bjsports-2016-096178
• Vuurberg G, Hoorntje A, Wink LM, van der Doelen BFW, van den Bekerom MPJ, Dekker R, et al. Diagnosis, treatment and prevention of ankle sprains: update of an evidence-based clinical guideline. British Journal of Sports Medicine, 2018;52(15):956. doi:10.1136/bjsports-2017-098106
• Gribble PA, Bleakley CM, Caulfield BM, Docherty CL, Fourchet F, Fong DT, et al. Evidence review for the 2016 International Ankle Consortium consensus statement on the prevalence, impact and long-term consequences of lateral ankle sprains. British Journal of Sports Medicine, 2016;50(24):1496–1505. doi:10.1136/bjsports-2016-096189
• Viljoen CT, Janse van Rensburg DC, Verhagen E, van Mechelen W, Tomas R, Schoeman M, Scheepers S, Korkie E. Epidemiology of injury and illness among trail runners: a systematic review. Sports Medicine, 2021;51:917–943. doi:10.1007/s40279-020-01418-1