Shin Splints (MTSS).
Shin splints — medically known as medial tibial stress syndrome (MTSS) — are the most common running injury in beginners, accounting for up to 35% of all running injuries. The pain presents along the inner edge of the shinbone (tibia) and is caused by overload of the bone and surrounding tissue, typically from doing too much too soon.
Overview
Medial tibial stress syndrome is a bone stress injury affecting the tibia (shinbone) and its periosteum — the membrane covering the bone that contains pain-sensing nerve fibres. MTSS exists on a clinical continuum with tibial stress fracture: MTSS represents diffuse bone stress (the milder end), while stress fracture represents localised bone failure (the severe end). Early recognition and appropriate load modification prevent progression along this continuum. MTSS accounts for 13-17% of all running injuries and up to 35% of injuries in beginner runners, making it the most common injury in new runners by a significant margin.
Causes and biomechanics
The primary cause is training load error — increasing weekly running volume or intensity faster than the tibial bone and periosteum can adapt through the bone remodelling cycle (which takes 6-8 weeks per cycle). Contributing biomechanical and risk factors include running on hard surfaces (concrete produces 30% more tibial impact force than grass), worn-out shoes with degraded cushioning, excessive overpronation, weak calf muscles (both gastrocnemius and soleus), weak foot intrinsic muscles (tibialis posterior in particular), low bone mineral density, female sex (women are 1.5-3x more likely to develop MTSS), prior history of MTSS, and insufficient calcium or vitamin D intake.
Symptoms
Diffuse, aching pain along the medial (inner) border of the tibia, typically spanning 5 cm or more of the bone surface. Pain is characteristically worse at the start of a run, may partially improve as the area warms up during the session, and returns with increased intensity after cooling down. The key clinical distinction: diffuse tenderness along a broad area of the shin suggests MTSS, while point tenderness at a specific spot (reproducible with one-finger palpation) may indicate a tibial stress fracture and requires imaging (MRI is the gold standard). If point tenderness is present, stop running immediately and seek medical assessment.
Treatment
Reduce running volume by 40-60% and replace running days with low-impact cross-training that does not reproduce the pain — cycling, swimming, deep-water running and elliptical are all effective alternatives. Apply ice for 15 minutes after any weight-bearing activity. Begin progressive calf strengthening: standing calf raises with straight legs (3x15), seated calf raises with bent knees (3x15), and toe walks (3x30 seconds) to strengthen the tibialis posterior and foot intrinsic muscles. If pain persists beyond 3 weeks despite load reduction, see a sports medicine physician for imaging to rule out tibial stress fracture.
Prevention
Follow the 10% rule for weekly volume increases — no exceptions during the first 6 months of running. Rotate two pairs of running shoes with different cushioning profiles and midsole geometries to vary the loading pattern on the tibia. Run on softer surfaces (grass, trail, track) when possible — even 1-2 sessions per week on soft ground reduces cumulative tibial stress. Maintain calf strength year-round with standing and seated calf raises (3x15, twice per week). For new runners: use a structured walk-to-run programme like STRIDD's beginner plan that builds volume gradually over 8-12 weeks with built-in adaptation time.
Return to running
Resume running only when you can walk briskly for 30 minutes completely pain-free on consecutive days. Then progress through a structured run-walk protocol over 2-3 weeks: start with 1-minute run intervals separated by 2-minute walks, progressing to 3-minute runs with 1-minute walks. Increase continuous running time by no more than 5 minutes per session. Return to full pre-injury training volume gradually over 4-6 weeks. Maintain calf and tibialis posterior strengthening exercises as a permanent part of your routine — they are not optional and should continue indefinitely to prevent recurrence.
Frequently asked questions
What do shin splints feel like?
Shin splints present as a diffuse, aching pain along the medial (inner) border of the tibia — typically spanning 5 cm or more of the bone's length. The pain is characteristically worse at the start of a run, may ease partially as the area warms up, and returns more intensely after cooling down. If you can reproduce pain at a single fingertip-sized spot instead of along a broad line, that may be a tibial stress fracture and requires imaging — stop running and see a sports physician.
How long do shin splints take to heal?
Mild MTSS usually resolves in 3-6 weeks with 40-60% volume reduction, cross-training, and progressive calf strengthening. More persistent cases take 8-12 weeks. Expect a longer timeline if you continue running through escalating pain, if you have low bone density, or if the pain is accompanied by significant overpronation. Imaging (MRI) is warranted if symptoms persist beyond 3 weeks despite proper load management.
Are shin splints and stress fractures the same?
No — they exist on the same continuum but represent different severities. Shin splints (MTSS) are diffuse bone stress along a broad area of the tibia. Stress fractures are localised bone failure at one specific spot, reproducible with one-finger palpation. Ignoring MTSS and continuing to run often progresses the injury into a stress fracture, which requires 6-8 weeks of complete running rest and sometimes immobilisation.
Can I run through shin splints?
Only with significant volume reduction (40-60%), exclusively on soft surfaces, and only if pain stays below 3/10 during and after runs. Continuing normal training typically worsens MTSS and risks progression to stress fracture. Cross-training alternatives (pool running, cycling, elliptical) preserve aerobic fitness without bone-loading while the tibia remodels. A single session on concrete during the acute phase can set recovery back by weeks.
What shoes help with shin splints?
Shoes with moderate-to-maximal cushioning reduce tibial impact load, particularly for heel strikers. Rotate between two pairs of shoes with different cushioning profiles and midsole geometries to vary the repeated loading pattern on the tibia. Replace shoes every 500-800 km before midsole cushioning degrades. If excessive overpronation is visible, a stability shoe or motion-control shoe may reduce medial tibial load. Minimalist and zero-drop shoes are contraindicated during acute MTSS recovery.
Why do beginner runners get shin splints so often?
New runners often increase volume faster than their tibial bone and periosteum can adapt through the bone remodelling cycle, which takes 6-8 weeks per cycle. Combined with insufficient calf strength, hard running surfaces, and under-cushioned or worn-out shoes, this produces the highest injury rate of any running condition in beginners. A structured walk-to-run plan (like Couch-to-5K done over 8-12 weeks with conservative progression) dramatically reduces MTSS incidence.
Can I cross-train during shin splint recovery?
Yes, and you should. Non-impact or low-impact cross-training — swimming, pool running, cycling, elliptical, rowing — preserves cardiovascular fitness without bone-loading, letting the tibia remodel undisturbed. Many runners emerge from MTSS recovery with equal or better aerobic fitness if they cross-train diligently 4-5 sessions per week. Avoid jumping sports, uphill walking on hard surfaces, and any activity that reproduces shin pain during or after.
This article is for educational purposes only and does not constitute medical advice. If you are experiencing pain or injury, consult a qualified sports medicine physician or physiotherapist before modifying your training. Read our full medical disclaimer.