In the mid-1960s Marian Kegel won multiple medals at the Polish cycling championships, starting with bronze in both the road race and the cross-country events in 1964. One year later Kegel won silver in the cross-country race before winning gold in the team road race in 1966. During this time, he also rode in four editions of the Peace Race, winning the team competition in both 1967 and 1968. His best individual performance came at the 1966 UCI Road World Championships in Nürburgring when he finished fourth in the amateur road race. In 1968 Kegel represented Poland at the Mexico City Olympics, where he came 10th in the road race and sixth in the team time trial. Sadly he was only 27-years-old when he died in his hometown of Poznań in September 1972.