At the ICF Canoe Sprint World Championships, Fischer has won nine medals with three golds (K-1 4 × 200 m: 2009, K-2 200 m: 2007, K-2 500 m: 2007), four silvers (K-2 200 m: 2006, 2009; K-2 500 m: 2009), K-4 500 m: 2010, and two bronzes (K-2 500 m: 2005, 2006).