Modin first appeared at the 2007 Junior World Championships in Tarvisio, Italy . There he just missed a medal in fourth place in the sprint competition. He finished eleventh over 10 kilometers of freestyle . The good performance at the Junior World Championships enabled him to make his first start in the Cross-Country World Cup . In the sprint competition in Stockholm , he was only eliminated in the quarter-finals and, in 14th place, won World Cup points on his first appearance. In 2008 Modin won the silver medal in the sprint competition at the Junior World Championships in Mals . Over the distance of 10 kilometers, he was able to take sixth place. At the beginning of the 2008/09 season , Modin came to his second World Cup at the sprint in Kuusamo . The two-meter tall athlete made it to the semi-finals, but failed there. In the B final he was able to take second place and thus book eighth place in the final bill. After a few less successful starts in the World Cup, Modin took part in the middle of the season mainly in competitions of the Scandinavian Cup , where he won the sprint in Riga . In the overall ranking of the Scandinavian Cup he finished third this season . In March he reached the semi-finals of a World Cup sprint competition in his home town of Trondheim . With the tenth place he secured the 26th place in the overall World Cup ranking of sprint competitions. In the 2009/10 season, Modin achieved his first podium finish with third place in Rogla, Slovenia . At the 2010 Winter Olympics in Vancouver , he finished 18th in the sprint. In the 2010/11 season he came in second place in the team sprint at the World Cup in Liberec together with Mats Larsson . In all five sprint participations he was placed in the top ten. He achieved seventh place in the team sprint and fifth place in the sprint at the Nordic World Ski Championships in Oslo in 2011 . In February 2011 he became the Swedish sprint champion. He finished the season in third place in the Sprint World Cup. At the beginning of the 2011/12 season he came in 47th place at the Nordic Opening in Kuusamo. At the following World Cup in Düsseldorf he won his first World Cup victory together with Teodor Peterson . In nine sprint participations he came eight times into the points and thus reached the 25th place in the Sprint World Cup. Due to an illness, he only started again in the Scandinavian Cup in the 2013/14 season and in the World Cup again in Ruka in November 2014 , finishing in 70th place over 15 km. This was followed by starts in the Scandinavian Cup races. In February 2015 he won bronze in the sprint at the Swedish championships in Örebro . Last year he also won bronze at the Swedish championships over 50 km.
Modin announced the end of his career in April 2016.