[4] Her breakthrough year came in 1999: at the age of fifteen she took the junior silver medal at the 1999 IAAF World Cross Country Championships behind Werknesh Kidane.

Cheruiyot gained selection for the 2000 Olympic Games and reached the 5000 m final after setting personal bests in the qualifying rounds.

[5] Cheruiyot won the silver medal at the 5000 m final of the 2007 World Championships in Osaka, Japan with a time of 14:58.50, behind Meseret Defar in 14:57.91.

[6] In early 2009 she broke the Kenyan indoor 3000 m record with a time of 8:30.53 in Birmingham, and won the World's Best 10K race in Puerto Rico.

Cheruiyot won the women's 5000 m at the 2009 World Championships in Berlin with a time of 14 minutes 58.33 seconds, while countrywoman Sylvia Kibet took the silver.

She took victories in the 5000 m at the Meeting Areva and Memorial van Damme and was elected the inaugural Diamond League Trophy winner for the event on overall points.

[12] Another gold medal in the event came at the Commonwealth Games held that year in Delhi, where she headed a Kenyan podium sweep with Sylvia Kibet and Ines Chenonge.

[18] Her rival Masai led the initial charge at the World Cross Country Championships, but Cheruiyot broke away on the final lap to secure the gold medal and lead Kenya to the women's team title.