Double Olympic cross-country skiing gold medallist Martin Johnsrud Sundby has announced his retirement from the sport at the age of 36.
The four-time world champion has decided to pursue other challenges after calling time on his career, the Norwegian Ski Federation (NSF) said.
Sundby was not selected on the Norwegian cross-country team for the 2020-2021 World Cup season but competed at this year's Nordic World Ski Championships, finishing seventh in the 15 kilometres freestyle race.
The Norwegian athlete, who served a two-month doping ban in 2016, was a member of the squads which won gold in the 4x10 kilometres relay and team sprint events at the 2018 Winter Olympic Games in Pyeongchang.
He also earned silver in the 4x10km relay at Vancouver 2010 and in the 30km skiathlon at Pyeongchang 2018, and bronze in the 30km skiathlon at Sochi 2014.
Three of his world titles came in relay races - in 2011, 2017 and 2019 - with his individual triumph coming when he topped the podium in the 15km classic at the 2019 event in Seefeld.
Sundby claimed the overall Cross-Country World Cup crown in 2014, 2016 and 2017 and won a total of 30 races on the circuit during his career.
He racked up 73 World Cup podiums and became the first Norwegian to win the Tour de Ski in 2014.
NSF President Erik Røste paid tribute to Sundby following his decision to retire.
"Thank you for all the contributions both on and off the trail," Røste said.
"Thank you for all the magical moments we have experienced from the sofa corner in front of the TV with you as the main character.
"Good luck with new challenges."