Kammala jumlar da ke gaba: An haifi Chepkok a Kapkitony a cikin Gundumar Keiyo na lardin Rift Valley na Kenya. Ya lashe lambar azurfa a tseren matasa a gasar
2007 Gasar Cin Kofin Duniya, ta gama tara a Gasar Cin Kofin Duniya ta 2009 kuma ta bakwai a Gasar Cin Kofin Duniya ta 2009. Ya sami babban nasara na mita 5000 a kan layin IAAF Diamond League na 2010, ya ci nasara a gasar Grand Prix ta Burtaniya.