Valnes, who starts for Bardufoss og Omegn IF , took part in junior races from 2013 to 2016. In the 2016/17 season he mainly competed in the Nordic Scandinavian Cup . After two ninth places in FIS races in Muonio and Beitostølen and fifth place each in the sprint in Gålå at the beginning of the 2017/18 season, he made his debut in the World Cup in Lillehammer at the beginning of December 2017 . He got his first World Cup points with the 27th place in the sprint. In January 2018 he came back into the points in Dresden with 22nd place in the sprint and won the gold medal in the sprint at the U23 World Championships in Goms . In February 2018 in Trondheim he achieved his first podium finish in the Scandinavian Cup with second place in the sprint and at the end of the season he achieved tenth place in the overall ranking of the Scandinavian Cup. In the 2018/19 season he took third place in the sprint and first place in the sprint in Vuokatti at the Scandinavian Cup in Östersund and Madona , and thus achieved fifth place in the overall standings. In the World Cup she finished in the top ten four times and at the end of the season she finished 40th in the overall World Cup and 12th in the Sprint World Cup. He finished third in the sprint in Dresden and, together with Sindre Bjørnestad Skar, won his first World Cup victory in the team sprint. At the U23 World Championships in Lahti in 2019 , he won the gold medal in the sprint. In April 2019 he was third in the Reistadløpet . After finishing 12th in the Ruka Triple at the beginning of the 2019/20 season, he won the team sprint in Planica together with Sindre Bjørnestad Skar and took third place there in the sprint. This was followed by third place in the sprint in Oberstdorf and second in the sprint in Falun . In the 2020 ski tour, which he finished in 23rd place, he came third in the sprint in Trondheim and finally reached 12th place in the overall World Cup and second place in the Sprint World Cup.
Norway
Dresden
Planica
Vuokatti