He represented Austria in the 2004 Summer Olympics in men's mountain bike, cross-country[1] and is the 2011 XTERRA Triathlon world champion.

[5] In 2013, in his first race after serving his two-year doping ban, Weiss won Ironman Cozumel.

[6] In November 2011, Weiss was given a two–year ban for a blood doping infringement in 2005 while competing in mountain biking.

[7] NADA initially cleared Weiss in September 2010, but that decision was reversed a year later and subsequently issued the ban from competition.

[8] Weiss declared his innocence but chose not to appeal the ban, citing the time and expense that would be required to do so.