Nzau ndiye akava muKenya wokutanga kukunda mumutambo wemarathon wepasi rose paakakunda muChicago Marathon muna 1983. Gore rakatevera, Nzau akapedza ari wechinomwe mumakwikwi emarathon evarume kumaOlympics eZhizha a1984
. Mukuwedzera kumakwikwi emarathon, Nzau akapedza ari wechi14 pavanhu 16 vakapedza mumakwikwi evarume emamita 10 000 pamakwikwi mamwe chetewo. Muna 1990, Nzau akakunda Belgrade Marathon yokutanga.