Gaustad, who started for Hamar SK , ran his first race in the Continental Cup in Gjøvik in January 2001 , which he finished classically in 39th place over 10 km. In the 2003/04 season he achieved his first podium finish in Östersund with third place in the skiathlon and first place in Hommelvik over 15 km freestyle his first victory in the Continental Cup. He made his debut in the World Cup in February 2004 in Oslo , which he finished in 64th place over 50 km freestyle. In the 2004/05 season he took three wins in the Scandinavian Cup and won the overall standings. In March 2005 he achieved his first World Cup points in Lahti with 23rd place over 15 km freestyle. In the 2005/06 season he came eight times in the points in the World Cup, five of them in the top ten. In the Scandinavian Cup he won the 10 km freestyle in Haanja . He reached 28th place in the overall World Cup, 16th place in the Distance World Cup and sixth place in the overall ranking of the Scandinavian Cup. In the 2007/08 season he achieved five top ten placements, including third place in Tolga and first place in Vuokatti, each over 15 km freestyle, third place in the overall Scandinavian Cup standings. In his last active season in 2009/10 he reached in Beitostølen with the fifth place over 15 km freestyle his best result in the World Cup individual. He ran his last World Cup race in December 2009 in Davos , which he finished in 46th place over 15 km freestyle.
Norway
Sundsvall
Lapinlahti
Haanja