16/10/2026
Packing in training, time running & researching at 25-years-old?
"Her regular updates inspired many young athletes across Asia but away from the track she also pursued a demanding professional career as an artificial intelligence semiconductor researcher at the Korea Advanced Institute of Science and Technology."
Marathon runners can collapse or die from very different causes. In most cases, collapse is benign and related to circulation, while sudden death is usually caused by an underlying heart condition.
1. Collapse: usually exercise-associated collapse (EAC)
The most common cause of collapse after a marathon is exercise-associated collapse (EAC), accounting for roughly 59%–85% of medical encounters after races.
Main mechanism:
· During running, leg muscles help pump blood back to the heart.
· If a runner suddenly stops at the finish line, that pumping action stops.
· Blood pools in the legs, blood pressure drops, and the brain gets less blood flow.
· This causes dizziness, fainting, or collapse.
Other important causes:
· Exercise-associated hyponatremia – low blood sodium, often from drinking too much plain water. Severe cases can cause brain swelling, confusion, seizures, and death.
· Exertional heat stroke – dangerously high core body temperature.
· Hypoglycemia – low blood sugar, less common but possible.
· Dehydration – can contribute, but it is not the main cause of most post-race collapses.
2. Sudden death: usually hidden heart disease
Marathon-related sudden death is rare, but when it happens, it is most often due to a cardiac cause.
Younger runners (under 35)
Common causes include inherited or structural heart problems:
· Hypertrophic cardiomyopathy (HCM)
· Congenital coronary artery anomalies
· Ion channelopathies – e.g., long QT syndrome, Brugada syndrome
· Myocarditis
· Aortic dissection – e.g., in Marfan syndrome
These conditions often cause no symptoms and may not be found on a routine physical exam.
Older runners (35 and older)
The main risk is coronary artery disease:
· Plaque in the heart arteries can rupture during intense exercise.
· This can cause an acute heart attack and sudden cardiac arrest.
3. Key statistics
· Sudden cardiac death in marathons is rare: roughly 0.5–1 per 100,000 participants, depending on the study.
· The last 1.6 km / final mile accounts for a large share of cardiac arrests — often around 50%.
· Men are at higher risk than women.
· Survival has improved significantly with CPR and AEDs, from about 29% to 66% in some race settings.
4. How to prevent collapse
· Do not stop suddenly after crossing the finish line. Keep walking for several minutes.
· If you feel faint, lie down and raise your legs.
· Drink fluids with electrolytes, but avoid drinking excessive plain water.
· Acclimate to heat and pace yourself.
5. How to reduce sudden death risk
· Get a pre-participation cardiac screening, especially if you have symptoms or family history.
· Screening may include ECG, echocardiogram, and for older runners or those with risk factors, a stress test.
· Stop and seek help immediately if you develop:
· Chest pain or pressure
· Severe shortness of breath
· Fainting or near-fainting
· Palpitations
· Confusion, nausea, or unusual sweating
Bottom line: Most marathon collapses are due to postural blood pooling and are treatable. Deaths are rare and usually caused by undiagnosed heart disease. Race-day medical teams, AEDs, and CPR save lives.
Tragedy struck just moments from the finish line.