Yoo Ji-won was a 2001‑born graduate student at KAIST who studied AI semiconductors. She was also a running influencer who shared her training on social media. Her story is striking because she combined demanding research with competitive running.

On October 11, Yoo ran the Seoul half‑marathon. She collapsed at the 20.6‑kilometre point of the 21‑kilometre course. A race official performed CPR and she was taken to a hospital, but she did not regain consciousness and died after emergency care.

Yoo had finished the Seoul Marathon in 2 hours 56 minutes 32 seconds and had won the women’s masters 10‑kilometre race at the Gunsan Saemangeum Marathon. She said she arrived at her lab at 9 a.m. and ran for about two hours from 8 p.m. on days when work remained.

The race committee said no cause of death has been released and that it will review the incident and take follow‑up measures. Her sudden death shows how even high‑achieving students can face unexpected tragedy.