South Korean running influencer Yoo Ji-won, 25, has died after collapsing just 500 metres from the finish line of the Seoul Race half-marathon on October 11, 2026. She was taken to hospital but later died, organisers said. The cause of her death has not been officially disclosed, and race organisers said they would examine the incident.
South Korean running influencer Yoo Ji-won died after collapsing during a half-marathon in Seoul, with the 25-year-old falling ill just 500 metres from the finish line. She was taken to hospital but later died, according to the race organisers. The incident happened during the Seoul Race on Sunday, October 11, 2026. Ji-won was running the 21.1-kilometre event and reportedly collapsed at around the 20.6-kilometre mark. The cause of her death has not been officially disclosed yet.
Seoul Race organisers offer condolences
In a statement posted on Instagram on Monday, the Seoul Race organising committee said a participant had collapsed near the end of the race and was transported to a medical facility, where they later died, according to a report by People.
The committee expressed condolences to the deceased runner’s fellow participants and said it would examine the circumstances and take the necessary follow-up measures. The statement did not publicly identify the runner.
Ji-won was identified by her friend and fellow running content creator Bummy, who shared a tribute on Instagram. He said he noticed a crowd gathered near the finish line and initially thought someone had been injured. After completing the race, he looked for Ji-won at the awards podium, but then heard the news and rushed to the hospital.
In his post, Bummy expressed regret that he had been unable to remain by her side until the end. His account captured the shock felt by friends who had expected to celebrate the race with her.
Who was Yoo Ji-won?
Yoo Ji-won was a South Korean running influencer who shared her training sessions, race results and athletic achievements online. She had more than 9,000 followers on Instagram and was known among her audience for her enthusiasm for running.
Her last post was published on October 4, when she shared her time from a recent 10-kilometre run. Following news of her death, friends and followers left messages of condolence and remembered her as a talented runner.
Alongside creating running content, Ji-won worked as a graduate researcher in artificial intelligence semiconductors at the Korea Advanced Institute of Science and Technology (KAIST), according to reports and her Instagram bio. Her work in research and her commitment to sport made her sudden death particularly difficult for those who knew her.
Can a half-marathon cause a medical emergency?
Running can improve cardiovascular fitness, endurance and general health. However, long-distance events put significant strain on the body, and medical emergencies can occur even among young people who appear fit. There is no confirmed evidence that any particular medical condition caused Ji-won’s collapse.
One possible emergency during strenuous exercise is sudden cardiac arrest, when the heart unexpectedly stops pumping blood effectively. It can result from a dangerous heart rhythm and may sometimes occur in people with an undiagnosed heart condition. Cardiac arrest is rare at running events, but a sudden collapse must be treated as an emergency.
Exertional heatstroke is another serious risk, particularly during hot or humid conditions. When the body cannot cool itself, its core temperature can rise to dangerous levels and damage organs. Warning signs can include confusion, loss of coordination, vomiting, seizures or collapse. Urgent medical care and rapid cooling are vital.
Dehydration and electrolyte problems can also affect endurance athletes. Heavy sweating can reduce body fluids, while drinking excessive amounts of water without accounting for sodium loss can cause exercise-associated hyponatraemia, a dangerous fall in blood sodium. These are possible risks during endurance exercise, not established explanations for Ji-won’s death.
Warning signs runners should not ignore
Chest pain or pressure, unusual breathlessness, palpitations, severe dizziness and fainting during exercise should never be brushed aside as ordinary fatigue. Confusion, poor coordination or collapse, especially in hot conditions, also require immediate medical attention. Anyone experiencing such symptoms should stop exercising and seek help.
Runners can reduce some risks by building distance gradually, allowing enough recovery, adjusting their effort to weather conditions and drinking sensibly without overhydrating. People with known health conditions or symptoms during exercise should seek medical advice before taking on strenuous events.
Being young and physically active does not eliminate the possibility of an underlying medical problem. At races, organisers’ medical teams and bystanders should treat a collapse as an emergency and seek prompt professional assistance.
The cause of Yoo Ji-won’s death remains unconfirmed. Her death has left friends and followers mourning a young runner whose online posts reflected her passion for the sport. It is also a reminder that a collapse during endurance exercise needs an immediate medical response, rather than being assumed to be simple exhaustion.