Alongside her apprenticeship as trainer and philologist she started a successful ski racing career. In 1934, she won all titles at the German Championship. At the world championship in St. Moritz she won the slalom and the combined competition and was second in downhill (after Swiss Anny Rüegg). She won all titles at the world championships in 1937 (Chamonix) and 1939 (Zakopane). To this day, Cranz remains the most successful competitor at the World Championships, with twelve gold and three silver medals. In the 1930s, the championships were held annually.