She had participated in six marathons, had a taekwondo black belt and led an active life.
But she collapsed 150m from the finishing point of the Nike We Run 10km event on Sunday.
Ms Wu Kai Ling, 25, was pronounced dead at the Singapore General Hospital that day.
She had collapsed around noon, near Raffles Boulevard.
Lianhe Wanbao reported that she was an engineer with ST Electronics.
A Nike spokesman told the Chinese evening daily that after Ms Wu collapsed, medical personnel administered first aid before she was sent to the hospital.
Her death shocked her family.
Ms Wu's grandaunt said: "My grandniece would exercise often and has participated in six marathons."
She added that her grandniece was always healthy, but had complained about having a flu a few days before the run.