Later in the 1987 season, Chepkurui competed in the second-ever World Championships in Athletics in both the 400 m and the 4 × 400 m. She did not advance to the finals in either event.
In 1988, Chepkurui moved up to the 800 metres, culminating in August with a 1:58.1 hand-timed personal best which at the time was a Kenyan record and African record. Her national record stood until 2007.[4] She was viewed as a gold medal favorite for the 1988 Summer Olympics, but she was withdrawn from competition before the Games started.[5] The IAAF does not list any results for Chepkurui past 1988.[1]