1998 and 1999 took Rasmussen together with Lasse Bork each fifth place at the Junior World Championships. In 2001 he first appeared with Rasmus Quist, at the World Rowing Championships in 2001 occupied the two sixth place. The following year she won bronze in Seville with her first World Cup medal. At her first Olympics start in 2004 in Athens Quist Rasmussen and reached the fourth place, after they had previously won her first World Cup race in Poznan. 2005, the two started on the Dorney Lake in Eton in the lightweight single sculls, Rasmussen won ahead Quist. At the World Championships in Gifu, the two silver behind the Hungarian double sculls received. Your first world title erruderten Quist and Rasmussen, 2006 at Dorney Lake in Eton. Reached in 2007, the two Danes four wins in the four major race of the year: World Cup victories in Linz, Amsterdam and Lucerne as well as at the World Championships in Munich. 2008, the two won the World Cup only a second place in Poznan, at the Olympic Games in Beijing were the two bronze behind the British and the Greek boat.
After that Rasmussen and Quist separated. 2009 rowed Rasmussen Leichtgeichts - One and won in this class of boat bronze at the World Rowing Championships 2009 in Posen, 2010 entered Rasmussen very unsuccessful with Thomas Larsen in the heavyweight double sculls at. It was not until 2011, Quist and Rasmussen found again in the lightweight double sculls. After two third place finishes in the World Cup, they finished fifth at the World Championships. 2012 reached the two in the World Cup fourth place and two third places. The Olympic Regatta 2012 was held on Lake Dorney Eton, the regatta course, had on the Quist and Rasmussen reached their World Cup double victory and won their first world title. In the Olympic final in 2012, the two Danes won just ahead of the British Olympic champions in 2008 and 2010 and 2011 world champions Zac Purchase and Mark Hunter.
Rasmussen has a contest weight of about 69 kg at a height of 1.83 meters. He rowed for the Danske students Marketers Roklub in Copenhagen.