As a member of the Vándorkedv KK team, János Henzsel won the 1909 Hungarian 100-km Individual Road Race Championship. In 1912, he participated in the same event at the Stockholm Olympics, as well as being part of the team event. He subsequently rode for the Edison, Törekvés and Világosság KK teams. After finishing his competitive cycling career, Henzsel worked as a motorcycle and car mechanic in Budapest. He later competed as a motorsport racer, participating in a number of national and international competitions.