During the 2004–05 FIS Cross-Country World Cup, Bjørnås and fellow Norwegians Vibeke Skofterud, Hilde Gjermundshaug Pedersen, and Marit Bjørgen won the 4x5km relay race in Gällivare, Sweden. In the same season, the same four came third in the 4 × 5 km relay in Val di Fiemme, Italy. Bjørnås, Pedersen, Kristin Mürer Stemland, and Bjørgen also came second in the 4 × 5km relay in Falun, Sweden. In 2005, she won the 30 km classical event at the . She came 27th in the Women's sprint event at the FIS Nordic World Ski Championships 2005. Her best individual result at the FIS Cross-Country World Cup was seventh place in the 2006 15 km double staggered start race in Sapporo, Japan.