Løseth won the 2003 Trofeo Topolino and 2003 and 2004 the slalom of the Whistler Cup . In January 2005 she competed in FIS races for the first time , her debut in the European Cup followed in December 2005. In her very first season she established herself as one of the strongest slalom drivers. At the end of the season she finished second in the discipline classification behind the French Sandrine Aubert . She also won the bronze medal in slalom at the Junior World Championships in Mont Sainte-Anne in March 2006 .
After her first victory in the European Cup, Løseth moved up to the Norwegian World Cup team in February 2006 . In her third race she already achieved the first World Cup points of her career. After her first top 10 place in the slalom of Semmering in December 2006, she qualified for the 2007 World Championships in Åre , where she came tenth in the slalom. In the 2007/08 season she was able to score consistently in the slalom and mostly achieve placements among the top 15, with which she reached tenth place in the Slalom World Cup. Her best race result was fifth place in the Zagreb slalom on February 15, 2008.
Due to injury, Løseth was only able to take part in a few races in the winter of 2010/11. The 2011/2012 season was also not very successful, which is why it was mainly used in the European Cup. The following winter she caught up with the world's best and achieved fourth place in the slalom in Zagreb on January 4, 2013, the best World Cup result of her career to date. At the beginning of winter 2013/2014, Løseth also showed improvement in giant slalom and achieved her first top 10 result in this discipline on December 28, 2013 with ninth place at the World Cup in Lienz and fifth in slalom on December 29, 2013 Lienz. On January 4, 2015, she finished third in the Zagreb Slalom, achieving her first World Cup podium. At the end of the season, she was Norwegian champion in slalom for the second time after 2007.
Løseth celebrated her first World Cup victory on January 5, 2016 in the Santa Caterina slalom . In June she married her partner Herman Haver-Mathiesen in Lucca, Italy . Since the 2017/18 World Cup season , she has appeared under the name Nina Haver-Løseth. At the 2018 Winter Olympics in Pyeongchang , she won the bronze medal in the team competition.
At the end of December 2018, she suffered a fracture of the head of the tibia and a meniscus injury in a fall in the slalom on Semmering and had to take a break for the rest of the season. She made her comeback the following November, finishing fifth in the Levi slalom. Then she got five more placements in the top ten in slalom before she announced her retirement from competitive sport on March 20, 2020.
Norway
