Why Runners Get Shin Splints and How to Stop Them
Shin splints, medically called medial tibial stress syndrome (MTSS), cause pain along the inner edge of the shinbone. They affect 13-20% of runners and account for up to 60% of all lower-leg overuse injuries. The pain comes from repeated stress on the tibia and the connective tissues attaching muscles to the bone. The three primary drivers are training load errors (increasing volume or intensity too fast), muscle weakness (calves, tibialis anterior, hip stabilisers), and biomechanical factors (excessive navicular drop or ground contact asymmetry). Prevention is straightforward: increase weekly mileage by no more than 10%, strengthen the muscles that absorb impact forces, warm up properly, and address foot mechanics if your navicular drop exceeds 10 mm. Most cases resolve within 2-6 weeks when you reduce running volume and follow a targeted strengthening programme.
What Is Actually Happening in Your Shin
Medial tibial stress syndrome (MTSS) is not a single injury but a continuum. It starts as periosteal irritation (inflammation of the bone's outer lining) caused by repetitive tibial bending forces during running. If ignored, it can progress toward a tibial stress fracture. The tibialis posterior, soleus, and flexor digitorum longus muscles all attach along the medial tibia and pull on the periosteum with every stride.
Key risk factors from research: A systematic review of 3,500+ athletes found that a history of previous MTSS is the strongest predictor of recurrence (3.74x higher risk). Female runners are 1.71x more likely to develop it. Navicular drop greater than 10 mm nearly doubles the risk. Higher BMI and fewer years of running experience also increase susceptibility. Training errors alone are responsible for approximately 50% of all running injuries.
An Arion Running Analysis measures ground contact time, foot strike pattern, and left-right asymmetry to identify the biomechanical imbalances that drive tibial stress before they become painful.
How to Prevent Shin Splints
Training Load Management
- The 10% rule: Do not increase weekly running volume by more than 10%. Training errors account for roughly 50% of running injuries. This single rule eliminates the most common trigger.
- Alternate hard and easy days. Never stack two high-intensity or long-distance sessions back-to-back. The tibia needs 48-72 hours to remodel after high-impact loading.
- Avoid surface changes. Switching suddenly from treadmill to concrete or from flat roads to cambered surfaces increases tibial stress. Introduce new surfaces gradually.
- Replace shoes at 500-700 km. Worn midsoles lose shock absorption, transferring more impact force to the tibia.
Strengthening Exercises (3x per week)
- Calf raises (seated and standing): 3 x 15 reps each. The soleus and gastrocnemius absorb the majority of ground reaction forces during running. Weak calves shift that load onto the tibia.
- Tibialis anterior raises: 3 x 20 reps. Stand with your back against a wall, heels 30 cm out, and lift your toes toward your shins. This muscle decelerates the foot after heel strike and is often undertrained.
- Single-leg heel drops (eccentric): 3 x 12 per leg. Stand on a step, raise on both feet, lower on one. Builds eccentric calf strength that controls landing forces.
- Glute bridges: 3 x 15. Hip weakness causes compensatory loading patterns that increase tibial stress.
- Toe scrunches with towel: 3 x 30 seconds. Strengthens the intrinsic foot muscles that support the arch and reduce navicular drop.
Warm-Up Protocol
- 10-15 minutes of dynamic warm-up before running. Evidence shows this reduces shin splint risk.
- Include leg swings, calf pumps, ankle circles, and walking lunges.
- Never start a run at race pace. Build up speed gradually over the first kilometre.
Footwear and Biomechanics
- Runners with navicular drop above 10 mm benefit from a structured insole with firm arch support and a deep heel cup. This limits the excessive medial loading that drives tibial stress.
- If your shin pain is worse on one side, ground contact asymmetry may be the cause. A gait analysis can identify whether one leg absorbs more force than the other.
- If you have tried standard prevention and shin splints keep returning, a Shapes HYROX Edition insole provides structured arch support that reduces navicular drop and distributes impact forces more evenly across the foot. Pair it with an Arion Running Analysis to quantify the biomechanical factors driving your shin pain.
FAQ
What causes shin splints when running?
Three main causes: increasing training volume or intensity too quickly (the most common trigger), weak calf and tibialis anterior muscles that cannot absorb impact forces, and biomechanical issues like excessive navicular drop or ground contact asymmetry. Training errors alone account for approximately 50% of running injuries.
How do I prevent shin splints as a beginner runner?
Follow the 10% rule for weekly mileage increases, do calf raises and tibialis anterior exercises 3 times per week, warm up for 10-15 minutes before running, and replace running shoes every 500-700 km. Beginners with fewer years of running experience are at higher risk, so conservative progression is essential.
Can I run through shin splints or should I stop?
If pain is mild and does not worsen during your run, you can reduce volume by 30-50% and continue. If pain increases during running, is present when walking, or is localised to one sharp spot (possible stress fracture), stop running and consult a physiotherapist. Continuing to run through worsening shin pain risks progression to a tibial stress fracture.
Do insoles help with shin splints?
Insoles help when shin splints are driven by excessive navicular drop or pronation-related tibial loading. Research shows that shock-absorbing insoles can reduce stress fracture risk significantly. A firm, supportive insole with a deep heel cup is more effective than a purely cushioned insole. They work best alongside a strengthening programme, not as a standalone fix.
How long does it take for shin splints to heal?
Most cases resolve in 2-6 weeks with reduced training volume, targeted strengthening, and proper recovery. Severe cases or those that have progressed toward stress reactions may take 8-12 weeks. Return to full volume gradually, halving your previous distance and building back up over 3-4 weeks.
What exercises prevent shin splints?
The most effective exercises target the muscles that absorb running impact: standing and seated calf raises, tibialis anterior wall raises, single-leg eccentric heel drops, glute bridges, and toe scrunches. Do these 3 times per week. Consistency matters more than intensity. These exercises strengthen the kinetic chain that protects the tibia during running.
