She skated for the club SC Karl-Marx-Stadt and represented the GDR (East-Germany). Her coach was her mother Jutta Müller. Seyfert was a long-time rival of Peggy Fleming (U.S.), but could never win against her. She was one of the first world famous sport-stars of East Germany. In 1966, after two silver medals at the Europeans and the Worlds, she was voted as “The GDR female athlete of the year”. In 1968 she became the first woman to land a clean triple loop.