Bjervig had his first appearance in the cross-country skiing world cup in February 1995 at the world cup in Oslo . However, he only finished 53rd out of 66 participants. In March 1997 he won World Cup points for the first time with tenth place in the sprint competition in Sunne . His breakthrough to the top of the world came in the 1998/99 season when, after finishing second in Toblach, Italy, he celebrated his only World Cup victory over the same distance over 15 kilometers in the Estonian Otepää . At the end of the season he finished seventh in the overall World Cup ranking. In the sprint races, he just missed the podium in fourth. At the Nordic World Ski Championships in 1999 in Ramsau am Dachstein , he was eighth over 10 kilometers classic. Together with Erling Jevne , Bjørn Dæhlie and Thomas Alsgaard , he won the silver medal in the relay competition. In the pursuit competition he reached 14th place. In the following year he took second place three times in World Cup competitions and thus fought for eighth place in the overall World Cup ranking. After he was able to post some top ten results in the 2000/01 season , he later failed to build on these achievements. Bjervig's last international competition took place at the last relay competition of the 2002/03 season in Falun , where the Norwegian relay came fourth.