Falla made her
World Cup debut with a classical sprint race in
Kuusamo on 29 November 2008, where she finished in 22nd place. She reached her first
World Cup podium in
Düsseldorf in her second ever World Cup race. With that promising start, Falla was given a spot in the individual sprint race at the
2009 FIS Nordic World Ski Championships in
Liberec, but she failed to qualify for the quarter-finals by finishing 39th in qualifying round. After a podium appearance in her rookie season, Falla could not make the World Cup podium for more than two years. During that span, her sixth-place finish at the classical sprint in
Kuusamo helped her to secure a spot in the Norwegian Olympic team for the
2010 Winter Olympics in
Vancouver. At the Olympics, she finished 20th in the
individual sprint event. Falla returned to World Cup podium in
2010/11 season with a third place at the classical sprint in
Otepää, then she backed up that performance with a second-place finish in
Drammen. At the World Championships, after setting the third fastest time in the qualification Falla took a fall in her quarter final heat and eliminated from the competition in that stage after finishing third in the heat. After the disappointment in the
individual sprint, Falla was not initially considered for the
team sprint but after the withdrawal of
Marit Bjørgen, she was selected for the event alongside
Astrid Uhrenholdt Jacobsen and the pair went on to take a bronze medal behind the Swedish and Finnish teams. in December
2011. In
2011/12 season, Falla won her first World Cup victory in a freestyle sprint race in
Rogla, Slovenia. She also reached four more podiums during the season and finished the season in second place in sprint rankings behind
Kikkan Randall. Falla started
2012/13 season in very good form with one victory and three podiums from her first three sprint races. She also reached a podium in a distance race for the first time, a 10 km mass start race in
Canmore, but her level dropped after mid-January, and she could not make a single top 10 in the remainder of the World Cup season. For the
team sprint race she teamed up with
Ingvild Flugstad Østberg but the pair missed the medals and finished in fourth place mainly due to
Østberg’s fall in the penultimate leg of the race. Falla has not started well to
2013/14 season and she managed to reach only one podium in World Cup sprints before the Olympics. She was left out in the team sprint since her teammates
Marit Bjørgen and
Ingvild Flugstad Østberg has shown better performance in classical discipline throughout the season. Although the reason was understandable for many, some people – including
Bente Skari – criticized the decision of putting
Bjørgen into the team instead of Olympic champion Falla. After the Olympics, Falla earned her sole World Cup victory of the season in the prestigious classical sprint race in
Drammen. In
2014/15 season, Falla recorded four World Cup podiums and her only victory of the season once again came in
Drammen. At the
2015 FIS Nordic World Ski Championships in
Falun, Falla earned her first World Championship gold medal in the
team sprint event with
Østberg, but once again she had to settle for bronze medal in the
individual sprint behind
Marit Bjørgen and
Stina Nilsson. Falla's best season to date in terms of wins came in
2015/16 season. She was the dominant force in sprint races of the World cup throughout the season by winning eight of eleven sprint races, she participated in and missed the podium only once in the entire season. With eight sprint victories, Falla equaled the
Petra Majdič’s record of most World Cup sprint victories in a single season. At the end of the season she clinched the seasonal sprint World Cup title for the first time in her career. where she won three gold medals in three races. In
2016/17 season, Falla defended her sprint World Cup title despite being outsprinted by Sweden's
Stina Nilsson in most of the sprint races. Although Falla has only one sprint victory compared to
Nilsson's six, she took the advantage in sprint rankings when
Nilsson opted not to ski in
Toblach and she maintained it until the end of the season. At the
2017 FIS Nordic World Ski Championships in
Lahti, Falla took the gold medal in the
individual sprint in a similar fashion to her Olympic title and won the only sprint title that has eluded her in her career. She set the fastest time in the qualification and won every heat she competed during the process, while her archrival
Nilsson was disqualified in the semifinal. By winning the gold medal, she became the second female skier to win
Olympic,
World and
World Cup sprint title after her compatriot
Marit Bjørgen who reached that triple crown in 2010 but Falla has the distinction of holding those three honours at the same time. During the championships, Falla added two more gold medals to her medal tally and finished the championships with three gold medals. Along with
Heidi Weng, she once again brought the World
team sprint title to Norway. She was also the member of the Norwegian relay team that won the gold medal in
4 × 5 km relay, running the opening classical leg. ==Personal life==