Karel Pešek is unique for having competed in a winter and a summer sport at the same Olympics, competing in both football and ice hockey at the 1920 Olympics. Initially, he played under his pseudonym, Káďa, for his youth club ČAFC Královské Vinohrady. In 1913, he was recruited by Sparta Praha, for whom he played until 1933, interrupted only by military service during World War I. With Pešek as a winger or midfielder, Sparta won the national title in 1919, 1922, 1926, 1927 and 1932. They also won the inaugural edition of the Mitropa Cup, in 1927. At the Antwerp Olympics, Karel Pešek played the first of his 44 matches for the Czechoslovakian team, scored one goal. After reaching the final in 1920, the Czechs walked out after 38 minutes in protest of the referee’s decisions, and they were promptly disqualified. In winter, Pešek played ice hockey rather than football, and he was also very successful in that sport. With Bohemia (1914) and Czechoslovakia (1922, 1925), he won the European title three times, in addition to a bronze medal at the Antwerp Games. Pešek retired from sports in 1934, after playing one season for SK Židenice. Pešek then worked for the Czechoslovakian Health Ministry, until he was fired for not being a member of the Communist Party in the early 1950s. He died of cardiac arrest, shortly after his 75th birthday.