Yoo Ji-Won Dies at 25: 'Too Thin' Comments Fuel Grim Speculation About Running Influencer's Final Race

South Korean running influencer Yoo Ji-won has died aged 25 after collapsing near the finish of a half-marathon in Seoul, prompting online speculation about her health despite no confirmed cause of death.

Yoo collapsed at the 2026 Seoul Race on 11 October, reportedly about 500 metres (0.31 miles) from the finish. Emergency responders treated her before she was taken by ambulance to a medical facility, where she later died. Online reactions have focused on her appearance, but they do not establish what caused the collapse.

Yoo Ji-Won Collapsed 500 Metres From the Finish

The incident occurred at about 8:49am near the 20.6-kilometre (12.8-mile) point, according to reports. Medical personnel provided emergency treatment, including cardiopulmonary resuscitation, before Yoo was transported by ambulance.

The Seoul Race organising committee announced her death on 12 October and expressed condolences. It also said it would examine the incident. As of the latest reports reviewed, no official cause of death had been publicly confirmed.

X Users Speculate About Yoo's Physique and Health

Some users on X commented on Yoo's appearance and questioned whether her physique could have affected her ability to complete long-distance races. One wrote: 'She doesn't look like she has a lot of muscle or fat on her body and I imagine that thing could be stressful for a smaller frame'.

Another comment read: 'That's really f****** sad man ED are no joke'. The post did not explicitly explain the abbreviation, and the comment does not establish that Yoo had an eating disorder.

A third user wrote: 'Sometimes there is a thing as being too healthy. Her heart couldn't handle it. May she fly in peace'.

These comments reflect individual reactions rather than verified medical information. No public evidence reviewed establishes that Yoo had a heart condition, an eating disorder or another specific health problem.

Her Final Instagram Post and Tributes

Yoo's last reported Instagram update was posted on 4 October and showed results from a 10-kilometre (6.2-mile) run, according to People. Tributes followed news of her death from fellow runners and people who had followed her running content.

Bummy, a friend and fellow running content creator, reportedly shared a tribute describing his attempt to reach the hospital, hoping to see Yoo one last time. The post did not provide a medical explanation for her death.

Yoo Balanced Running With Graduate Research

Yoo was a graduate student at the Korea Advanced Institute of Science and Technology (KAIST), researching artificial-intelligence semiconductors. In a March interview, she reportedly described arriving at the laboratory at 9am and running for about two hours from 8pm, sometimes returning to work afterwards.

Her results included a marathon time of 2 hours, 56 minutes and 32 seconds on 15 March 2026, while her half-marathon time was reported as 1 hour, 22 minutes and 1 second. She also won the women's masters 10-kilometre category at the Gunsan Saemangeum Marathon in April.

Her running achievements and research work have featured in tributes since her death, but neither her schedule nor her race results establish a link to the collapse. The organising committee said it would examine the incident. The cause of Yoo's death remains unconfirmed.