Bitok emerged in 1992 as a relatively unknown athlete. He qualified for the Barcelona Games at the Kenyan trials and defeated several world class athletes at the Bislett Games in Oslo. By the time of the Olympics he had established himself as one of the favourites. He narrowly lost the final to Dieter Baumann of Germany. A few weeks later he won the 5000 m race in Zurich. In the following years Bitok did not match his performances of 1992. However, by 1996 he was back and won another silver in Atlanta. He also won two World Indoor silvers (1997, 1999) in the 3000 metres behind Haile Gebrselassie.