The Norwegian, who won 4x6 kilometres relay gold on home snow at the World Championships in Oslo last year, has opted to hang up her skis and gun at the age of 29.

Birkeland won Olympic bronze in the same relay discipline at the Sochi 2014 Winter Games as well as two more relay bronzes at the World Championships.

She also claimed an individual World Cup win in the sprint event in Ruhpolding, Germany, in 2015.

"My plan was to go until the Olympics next year, but my form has not been so good," she said.

"I did everything to reach my goals, but still I had some trouble to make it to the top in my competitions. 

"It is hard to put so much work into it every day and not get any results that I want. 

"Twenty-nine is not so old, but I have been in this game for some time and it feels right now.

"When I started in the World Cup my results were not so good, but in relay I had a strong team, so I was lucky to get some World Championship and Olympic medals. 

"The highlight of my career was my win in the Ruhpolding sprint in 2015. 

"It was unreal, as it was trouble for me to make a perfect race, and that was my day to get the opportunity to be on top of the podium. 

"I wanted to do it again, but I never managed it."