József Braun started his sports career at the age of 13 as a youth footballer of VAC. Two years later, Jimmy Hogan, the coach of MTK, invited Braun to join the team., and on 6 October 1918, he played with the national team for the first time. In 1919, he was chosen as the Hungarian player of the year. In 1924, Braun, under the Magyarized name of Barna, was a member of the Olympic team. His last national match took place in 1926. Barna earned 27 caps, and scored 11 goals with the national team. In 1921 he was seriously injured, but was able to continue his sports career, retiring in 1931. Braun won eight Hungarian championship titles while coaching MTK. Between 1937 and 1939, he worked as a coach for Slovak SK Bratislava. In 1943 he died in labor service.