Athletes from 50 countries participated in the event at the Miramar beach.
A 26-year-old participant of the IRONMAN70.3 race in Panaji died at a hospital here on Monday, a day after he collapsed during the event, police said. The man, Kamakhya Siddharth, hailed from Patna.
The Ironman Triathlon includes a swim, a bicycle ride and a marathon that has to be completed by the participants.
"Kamakhya Siddharth, who collapsed during the IRONMAN 70.3 on Sunday, died at a private hospital on Monday," Superintendent of Police (North) Nidhin Valsan told PTI.
He said Siddharth had suffered multiple organ failure. Siddharth collapsed during the last leg of the race in Panaji on Sunday afternoon following which he was shifted to a private hospital.
Athletes from 50 countries participated in the event which began at the Miramar beach.