[3] Brandl qualified for the men's 400 m freestyle at the 2008 Summer Olympics in Beijing, by attaining a B-standard entry time of 3:51.35 from the Austrian Swimming Championships, coincidentally in his home city Linz.

Brandl and his teammates Markus Rogan, Dominik Koll, and Florian Janistyn finished heat two in fifth place and ninth overall, for another Austrian record time of 7:11.45.

The following year, Brandl achieved a fifth-place finish in the same event at the 2010 European Short Course Swimming Championships in Eindhoven, Netherlands, posting his best career time of 3:44.33.

[7] At the 2011 FINA World Championships in Shanghai, China, Brandl competed in two long-distance freestyle events, but achieved a slightly fair swimming performance.

[10] He challenged seven other competitors on the third heat of his only individual event, including Canada's Blake Worsley and Israel's Nimrod Shapira Bar-Or.