Career
He also took part in the 2010 IAAF World Cross Country Championships in Bydgoszcz, Poland, finishing fourth in the junior men"s race. On 11 February 2011, Koech became just the fourth man to run the 5000 m indoor under 13 minutes when he clinched victory in 12 minimum 53.29 sec at the Social Democratic Party Bank Meeting in Düsseldorf. He then ran a world junior indoor best for the 3000 m at the Indoor Flanders Meeting a few days later, running a time of 7:37.50 minutes Koech controlled the junior race at the Kenyan Cross Country Championships and took first place, earning a spot for the Junior World Cross.
Despite being a provisional favourite for the junior race at the 2011 IAAF World Cross Country Championships, he ended the race in tenth place, although he did help Kenya to the team title alongside Geoffrey Kipsang and Patrick Mutunga Mwikya.
Moving into the senior ranks, he ran over 5000 m at the 2011 World Championships in Athletics and closely finished behind the medallists to place fourth overall.