Rebecca TaylorThe Brighton Marathon 2026 takes place on Sunday 12 April, with up to 20,000 runners setting off from Preston Park toward Madeira Drive in one of the UK's most scenic and popular mass-participation events. As Britain's third-largest marathon, the race attracts everyone from elite athletes to first-time finishers — and with that diversity comes an equally wide range of injuries. Sports medicine doctors who work major UK road races know exactly which problems emerge in the final days of training and the first hours after the finish line.
The most common marathon injuries seen by sports doctors
According to data published by the British Journal of Sports Medicine, running-related injuries affect between 19% and 79% of recreational marathon runners each year, depending on training load. The most frequent complaints reported by runners in the final week before race day and in the immediate recovery period include:
Iliotibial band (ITB) syndrome — a sharp pain on the outside of the knee that often strikes between kilometres 25 and 35. The ITB is a thick band of fibrous tissue running down the outer thigh, and it becomes inflamed when mileage increases too quickly. In a 42.2km race, even a small biomechanical issue compounds with every stride.
Plantar fasciitis — heel and arch pain caused by inflammation of the thick band of tissue along the bottom of the foot. Many runners arrive at race day with a low-grade case they've been managing for weeks; the sustained effort of a marathon can acutely worsen it.
Shin splints (medial tibial stress syndrome) — a dull, aching pain along the inside of the shinbone. Often dismissed as mild, shin splints left untreated can progress to stress fractures — a significantly more serious diagnosis.
Runner's knee (patellofemoral pain syndrome) — diffuse pain around or behind the kneecap. Particularly common in runners who have overtapered in the final two weeks, causing biomechanical changes in stride.
Muscle cramps and hyponatraemia — in longer events, electrolyte imbalances become a genuine clinical risk. Hyponatraemia (low blood sodium from drinking too much plain water) caused several hospitalisations at major marathons in 2025, according to race medical teams.
What happens to your body during a marathon
Running 42.2 kilometres puts extraordinary stress on the musculoskeletal system. By kilometre 30, glycogen stores are typically depleted — the phenomenon runners call "hitting the wall." At this point, the body switches to burning fat, a slower process that produces noticeable fatigue and cognitive slowing.
Each foot strike in running generates a ground reaction force of roughly 2.5 to 3 times your body weight. Over a marathon at an average stride length of 1.5 metres, that's approximately 28,000 foot strikes per leg. Tendons, joints, and bones must absorb this cumulative load — which is why many injuries don't present until the final third of the race.
Core body temperature in a running marathon can rise to 39–40°C even in cool conditions. In Brighton, April temperatures average 10–13°C, which actually provides favourable racing conditions — but runners who overdress or underhydrate risk heat stress regardless of ambient temperature.
The two days after the race: when to seek medical advice
Many runners experience delayed onset muscle soreness (DOMS) 24–48 hours after the finish. This is normal and resolves with rest, hydration, and gentle movement. However, certain symptoms warrant prompt medical attention:
- Chest pain, palpitations, or difficulty breathing — rare but serious; seek emergency care immediately
- Dark or tea-coloured urine — a sign of rhabdomyolysis (muscle breakdown releasing proteins into the bloodstream), which can damage the kidneys
- Persistent swelling in a specific joint, not generalised muscle soreness — this may indicate ligament damage rather than DOMS
- Pain that prevents you from bearing weight — a potential stress fracture requires imaging to rule out
- Unusual neurological symptoms — numbness, tingling, or weakness in a limb beyond 48 hours
If you ran Brighton and are experiencing any of these symptoms, see your GP or visit an urgent care centre without delay. For musculoskeletal injuries that aren't emergencies — persistent knee pain, heel pain that worsens after rest, ankle instability — a sports medicine specialist or physiotherapist can assess whether you've sustained tissue damage that needs treatment.
How to recover well in the week ahead
The 7–10 days after a marathon are as important as the training cycle that preceded it. Sports medicine guidelines recommend:
No running for at least 7 days. The musculoskeletal microtrauma accumulated over 42.2km needs time to repair. Attempting to run on day 3 or 4 dramatically increases the risk of converting a minor strain into a serious injury.
Gentle walking and swimming from day 2 or 3 promotes circulation and recovery without impact stress. Cycling on a stationary bike is also well tolerated.
Rehydrate with electrolytes, not just water. Sodium, potassium, and magnesium need replenishing, particularly in the 48 hours post-race.
Prioritise sleep. Growth hormone — critical for tissue repair — is primarily released during deep sleep. Runners who sleep fewer than 7 hours in the recovery week have statistically slower healing times.
Ice, not heat, for acute joint inflammation in the first 48–72 hours. After 72 hours, heat can support muscle relaxation.
Disclaimer: This article provides general health information and does not replace personalised medical advice. If you have specific concerns about an injury or your recovery, consult a qualified healthcare professional.
The bigger picture: amateur runners and sports medicine access
The Brighton Marathon exemplifies a UK-wide trend: mass-participation running events are growing rapidly, but access to sports medicine expertise for recreational runners remains inconsistent. NHS physiotherapy waiting times in England averaged 12.2 weeks in Q4 2025, according to NHS England data — a significant gap when a runner needs a diagnosis within days of race weekend.
Private sports medicine consultations offer a faster route to diagnosis and rehabilitation planning. On Expert Zoom, you can find qualified sports medicine doctors and physiotherapists available for appointments within days, whether you need an initial assessment, imaging referral, or rehabilitation programme following the Brighton Marathon 2026.
The marathon is a remarkable physical achievement. Taking recovery as seriously as training is what allows runners to do it again.
