Running Influencer Yoo Ji-won Dies After Seoul Half-Marathon Collapse
KAIST researcher and athlete passes away after collapsing near the race finish line.
1Tragic Incident in Seoul
Yoo Ji-won, a 25-year-old running influencer, collapsed at the 20.6-kilometre mark during the 2026 Seoul Race on October 11. Despite receiving immediate CPR from officials near Gwancheol-dong and being transported to a medical facility by ambulance, she later passed away. The Seoul Race Organising Committee officially confirmed her death on October 12.
2Academic and Athletic Profile
Beyond her social media presence, Yoo was a dedicated graduate student at KAIST, specializing in artificial intelligence semiconductors. She balanced rigorous laboratory research with an intense running schedule, documenting her progress to over 9,000 followers on Instagram. Her academic focus highlighted a disciplined approach to both high-level technical studies and endurance sports.
3Competitive Running Achievements
Yoo demonstrated significant athletic growth since she began running in 2022. On March 15, 2026, she completed the Seoul Marathon in 2 hours, 56 minutes, and 32 seconds, successfully breaking the three-hour barrier. Additionally, she secured a victory in the women's masters 10-kilometre category at the Gunsan Saemangeum Marathon held this past April.
4Race Day Emergency Response
The Seoul Race event, which started at Seoul Plaza, hosted approximately 12,000 participants across half-marathon and 11-kilometre courses. The emergency occurred at 8:49am, just 500 metres from the half-marathon finish line. The Seoul Metropolitan Government confirmed that officials provided immediate on-site treatment before the ambulance transfer, though the specific cause remains currently undisclosed.
5Community and Peer Tributes
The running community has expressed deep sorrow following the news of her passing. Fellow content creator Bummy, who was present at the race, shared a tribute after attempting to reach the hospital to see her. Her Instagram account, previously used for sharing training milestones, has transitioned into a digital space for followers to offer condolences.
6Ongoing Official Investigation
The Seoul Race Organising Committee has stated that they will closely examine the circumstances surrounding the incident. While the exact medical cause of the collapse has not been publicly disclosed, organizers are committed to taking necessary follow-up measures. The committee has also expressed formal condolences to Yoo's family during this difficult period.
7Balancing High-Performance Demands
In a March interview, Yoo discussed the challenges of integrating long evening runs with her demanding laboratory research at KAIST. Her public updates often showcased the intersection of her technical career and athletic pursuits. This balance remains a common theme among high-achieving professionals who utilize endurance training to manage the stress of research.
8Impact of Sudden Loss
The death of a prominent young athlete and researcher highlights the unpredictable risks associated with high-intensity endurance events. As the investigation proceeds, the focus remains on respecting the privacy of her family. Her legacy as both a dedicated AI researcher and a disciplined runner continues to resonate within her professional and athletic communities.