Kimaiyo now works as a marathon coach, and trains current women's world record holder Brigid Kosgei.

[a][2] Kimaiyo broke away from Muindi and Thabiso Moqhali after 25 miles (40 km) of the race, on the ascent of Diamond Head.

[12] Kimaiyo ran in the 2000 Berlin Marathon, but dropped away from the lead group 10–20 kilometres (6.2–12.4 mi) into the race.

[15] Kimaiyo now works as a marathon coach, and runs a training camp in Kapsait, Kenya at an altitude of 9,600 feet (2,900 m).

[18] Kimaiyo has also trained Edward Zakayo, who won the 5000 metres event at an under-20 World Championships,[17] Christopher Kipkosgei, who finished second to Kimaiyo at the 2003 Baltimore Marathon after training with him for half a year,[15] and Judith Korir, who won the 2022 Paris Marathon.