Mandy Benzien grew up in Gera. At the age of six, she started jumping water, changed two years later, but for the canoe slalom.
In 1990, she was delegated to the children and youth sports school ( KJS ) to Leipzig and was in the same year GDR youth champion in one kayak. In 1992, she failed to qualify for the first all-German junior national team and won with the kayak team silver at the Junior World Championships.
Her first big success in the performance class was the team's victory at the World Cup 1997 in Brazil Tres Coroas she could repeat in 1999. At the Olympic Games in Sydney in 2000 they finished sixth. In 2002 she was in the individual competition runner-up world champion. In the 2004 Olympics she placed 14th Place and in 2005 was again vice-world champion in the individual competition. After a maternity leave in 2006 she went to work back in 2007 with team gold and sixth place in the individual competition at the World Championships in Foz do Iguacu in the world rankings.
In 2008, Mandy Benzien took the qualification for the Olympic Games in Beijing in attack, for who could only qualify a German women's boat for the first time. However, in the national qualifying race they had to let go first world champion Jennifer Bongardt. In March 2009, she announced her retirement from competitive sport.
In her playing days, she went to Leipzig Canoe Club at the start.
Mandy Benzien has been married since 6 March 2009 with the internationally successful slalom canoeists January Benzien, who is also the father of her son born in 2006 Justus Jonas. In August 2009, the two are expecting their second child. Professional Planert has worked as a junior trainer at Saxon Canoe Association. She lives in Leipzig.