Troelsen started playing handball at Skjern Håndbold, but still as junior player she switched to Danish top club Viborg HK. Here she debuted in the top league Damehåndboldligaen in 2003. She did however not see much playing time at Viborg.
In 2007 league rivals SK Aarhus signed her, where she broke through to be a first team regular. But as the club had economic trouble she switched to FC Midtjylland Håndbold in the middle of the 2009/2010 season, despite the fact that she had to play as an amateur in the beginning of her tenure.[2]
In 2014 Troelsen started receiving less playing time, so she switched to French club Toulon Saint-Cyr Var Handball, where she played for one season before returning to Denmark. Here she joined Silkeborg-Voel KFUM, before in 2017 rejoining her old club, FC Midtjylland, which in the meantime had change name to Herning-Ikast Håndbold.[3]
She played here until the end of her career in 2019.[4]
National Yeam
She debuted for the Danish national team, and the same year she was at her first major international tournament.