The West German female field hockey team with Dagmar Breiken earned the silver medal at the 1984 Los Angeles Olympics in the round-robin tournament, finishing with 6 points. As Dagmar Bremer, she was also on the team placing fifth four years later at Seoul after a 4-2 win against Canada in the classification round. She also became World Champion runner-up in 1986. She also was European Indoor Champion 1985 and 1987 and won the bronze medal at the 1984 Europeans. She won 124 international caps (14 indoor) between 1982-88.
Domestically, Bremer played with Rot-Weiss Köln, RTHC Bayer Leverkusen and finally Eintracht Frankfurt. In 1984 she helped Leverkusen to win the German Indoor Championship and in 1985 the German Championship.