Volden won at the World Championships four silver medals, their first as a 19 -year-old in HREM World Cup debut in 1979 in Tampere, Finland, when she was with Anne Berit Eid and Astrid Carlsson second in the relay behind the team of Finland. 1981 in Switzerland, she was Annichen behind the Swede Kringstad vice world champion in the individual race. This placement could be repeated in Australia in 1985. Here they remained, again fell short Kringstad. Was successful as their participation at the Nordic Championships 1984 in Norway and 1986 in Åland. In both championships she managed the double triumph in the individual and team competition. With the season they won their fifth straight Nordic Cup in 1988. Volden 1987 could again win silver team, this time as the anchor leg on a team with Ragnhild Bratberg, Ragnhild Bente Andersen and Ellen Sofie Olsvik Also in World Championships.
Brit Volden is married to multiple World Orienteering Champion Øyvin Thon. She ran for the club Kongsberg IF.
In the overall World Cup in 1986, she was sixth in 1988 behind her teammate Ragnhild Bratberg at a gap of two points in second.