Erich Rademacher, a trained insurance salesman, was in his playing days as the best swimmers of Germany. He is called in a row with Arne Borg, Andrew Charlton, Gertrude Ederle, Duke Kahanamoku and Johnny Weißmüller as the most successful swimmers in the 20s of the 20th century.
His athletic career began at SC Hellas Magdeburg, in the boys' season in 1913 he won his first victory. Over a period of nearly 20 years, he started for this club.
He put in the time to 30 world records and won a variety of swimming but also water polo competitions. In 1924 he held all the world records over 100, 200, 400, and 500 meters in the chest style. At the end of his career, he could look back on 998 victories. Eight times he became German champion in the 100 meter breaststroke. He won the European Championship title and was able to win medals at the Olympics also. However, especially in its most powerful time he could not participate in the Olympic Games of 1920 and 1924, as Germany was excluded as a result of World War I from participating. He graduated in 1926 a swimming tour in the U.S. and 1927 in Japan. In 1928 he was with the German team Olympic champion in water polo.
His brother Joachim Rademacher was also a successful swimmer.
In 1972 he was inducted into the Hall of Fame of the international swimming sport. The city of Magdeburg named in his honor as a road Rademacherweg and a swimming pool.
In 2008 he was inducted into the Hall of Fame of German sport.