Career
He is a two-time Olympian, a 41-time national titleholder, a 5-time long and short course Austrian record holder. Koll is one of few LGBT Olympians to come out as gay. Koll made his Olympic debut at the 2004 Summer Olympics in Athens, competing in the men"s 200 m freestyle.
Koll cruised to fourth place and twenty-fifth overall by 0.53 of a second behind Latvia"s Romāns Miloslavskis in 1:51.36.
Four years after competing in his first Olympics, Koll qualified for his second Austrian team, as a 23-year-old, at the 2008 Summer Olympics in Beijing. He eclipsed a FINA A-cut time of 1:48.21 from the European Championships in Eindhoven, Netherlands.
In the 200 m freestyle, Koll set a new Austrian mark and recorded a sixteenth fastest time of 1:47.81 on the second night of preliminaries to secure a final spot for the semifinals. Followed by the next morning session, Koll failed to qualify for the final, as he finished his semifinal run with a fourth-slowest time of 1:47.87, just 0.06 of a second off his record from the preliminaries.
Two days later, Koll swam on the start-off leg of the men"s 4×200 m freestyle relay, recording his individual-split time of 1:47.72.
Koll and his teammates David Brandl, Markus Rogan, and Florian Janistyn finished the second heat in fifth place and ninth overall, for another national record-breaking time of 7:11.45. Shortly after the Olympics, Koll set another national record in the 400 m freestyle at the 2008 European Short Course Swimming Championships, with a time of 3:39.82. The following year, he posted his fifth-career Austrian record time of 1:43.90 by finishing eighth in the preliminary heats of the men"s 200 m freestyle at the European Short Course Swimming Championships in Istanbul, Turkey.