At the age of 16 Evensen sustained a life-threatening kidney injury in a serious fall on Granåsen in Trondheim and had to sit in a wheelchair for a while . Although, in the opinion of the doctors, he could never have jumped again, he continued to practice his sport. In 2004 he took part in the Norwegian Championship, where he took 25th place in jumping on Holmenkollen . In the following years he took part in other Norwegian championships, where a 15th place in 2007 in Molde was his best result. He also started in the Norges Cup, a national ski jumping series of the Norwegian Ski Association, and was able to win some of these competitions. In January 2007 he took part as a forerunner in ski flying in Vikersund . At the beginning of March 2007 Evensen finally started at the FIS Cup in Zaō, Japan, for the first time in an international competition. In his debut competition he was able to take second place, the next day and a week later in Sapporo he was even able to win the jumping. In mid-March he competed in a Continental Cup competition for the first time in Zakopane and came second. At the end of the season he again acted as a forerunner in ski flying, this time in Planica, Slovenia . At the beginning of 2008 he competed in other Continental Cups and was able to occupy several places among the top ten. At the end of the 2007/08 season, he was back in the lead in ski flying in Planica, where he set his personal best of 212 m. Although he only achieved mediocre placements in the 2008 Summer Jumping of the Continental Cup, he started the Ski Jumping World Cup for the first time in Trondheim in early December 2008 , where he immediately finished tenth. On December 14th, 2008 he reached his first podium with 3rd place in the jumping in Pragelato, which was canceled after one round .
After that, his form dropped significantly and he mostly fought for a place in the second round. At the Four Hills Tournament in Garmisch-Partenkirchen , he could not qualify for the actual competition as 55th in the qualification. After he finished two 21st places in the remaining tournament competitions and thus finished 24th in the overall tournament ranking, he was able to consistently place in the top thirty in the following World Cup competitions. He was therefore nominated for the Nordic World Ski Championships in 2009 and won the silver medal in the team competition. On February 14th, 2009 he took third place behind Harri Olli and Anders Jacobsen in ski flying in Oberstdorf . As a result, he was instrumental in the victory of the Norwegian team in the FIS Team Tour , in which this competition took place. When ski flying on the Kulm, he was able to set the maximum distance of the ski flying weekend at 210 meters. Since the round was restarted later because the approach was too long, his flight was not counted.
On February 11, 2011, Johan Remen Evensen improved the ski flying world record of Bjørn Einar Romøren , who jumped 239 meters in Planica in 2005 when he flew 243 meters in training for the first flying on the newly built ski jump in Vikersund . In the following qualification he improved this record again with a jump to 246.5 meters.
After not being considered for the nomination for the Ski Flying World Championships in Vikersund, Evensen announced his immediate resignation. He justified this on February 20, 2012 with health reasons and announced that he had made this decision on the Saturday before the announcement of the cadre nomination.