Austrian Nordic combined Michael Gruber specialised in speed events. He participated at the 2002 Salt Lake City and the 2006 Torino Winter Olympics. With Christoph Bieler, Mario Stecher and Felix Gottwald he won team bronze in 2002 and team gold in 2006. Individually, Gruber came 28th in the sprint in 2002, and 12th and 13th in the individual race and the sprint respectively in 2006.
Gruber won two National titles in 1999 (sprint) and 2005 (individual race). He added two more international medals with a team gold at the 2003, and a team bronze at the 2005 World Championships. Suffering a cruciate ligament tear in 2007, he retired the following year.
Austria