Nyorai mberi kweiyi ndima - Kosgei akatanga basa rake repasi rose semumhanyi wenyika uye muchengeti wemakomo. Akasvika pakuzivikanwa semutambi wechidiki muna 1997 paakatora menduru yebhuronzi yechidiki pa1997 IAAF World Cross Country Championships
, uye akasvikawo 1997 IAAF Grand Prix Final nokuda 3000 metres steeplechase. Akasimbisa mukurumbira wake nokugadza chinyorwa chenyika chevaduku chechiitiko chacho.