Nurmsalu, who was trained by his father Toomas, among others, started in an international competition for the first time in 2007 at the Junior World Championships in Tarvisio . In the sprint, he took 62nd place and 56th place in the individual competition. With the Estonian team he fought for 12th place. In the 2007/08 season he first appeared in the Nordic Combined B World Cup. His best result this season was 62nd place in the sprint competition in Vuokatti, Finland . At the Junior World Championship in Zakopane he reached places 58 and 47 in the sprint and individual competitions. As in the previous year, the Estonian team took 12th place. At the end of the season, he won his first Estonian championship title in the mass start competition. After he was able to place himself in the top 30 athletes several times in the Continental Cup at the beginning of the 2008/09 season , he was used in the World Cup for the first time . In his World Cup debut, he finished 42nd in Klingenthal . Compared to previous years, he significantly improved his results at the Junior World Championship. In Štrbské Pleso he fought for places 19 and 26 in the individual competition over 5 and 10 kilometers respectively. He finished eleventh with the team. The good results this season enabled him to start at the Nordic World Ski Championships 2009 in Liberec . His best result there was 35th place in the individual competition on the normal hill. With the Estonian team he was able to place himself in ninth place. His best result of the season was 19th place in the Continental Cup in Rovaniemi .
At the beginning of the 2009/10 season Nurmsalu achieved a respectable success in the World Cup. After the jumping competition, he and his compatriot Aldo Leetoja were able to take tenth place in Kuusamo . In cross-country skiing, however, he fell back to 38th place. In Ramsau am Dachstein he achieved his best result of the season with 35th place. Also this season he took part in the Junior World Championship . In Hinterzarten he finished 16 and 18 in the individual competition over 5 and 10 kilometers respectively. With the team he reached seventh place. At the Summer Grand Prix 2010 in Oberwiesenthal he again showed a good jumping performance and was able to start second in the cross-country competition. In the end he reached the 25th place. As in the previous year, Nurmsalu impressed at the start of the 2010/11 season in Kuusamo. After a tenth place in the jumping competition, he achieved his first World Cup point with 30th place. This was the first World Cup point that an Estonian athlete was able to achieve since the 2005/06 season . In January 2011 he won the Continental Cup in Klingenthal with the best jumping performance . Two weeks later he started at the Junior World Championships in Otepää, his home country . In the individual competition over the 10 kilometer distance, he won the jump competition and secured the bronze medal behind the German Johannes Rydzek and the Slovenian Marjan Jelenko . A day later he also started the ski jumping competition. After an FIS Cup in 2008, this was only his second international ski jumping competition. On the Tehvandi-Schanze , where he was able to become Estonian ski jumping champion for the first time at the turn of the year, he only had to admit defeat to the Bulgarian Wladimir Sografski and the Austrian Stefan Kraft and won his second bronze medal at the Junior World Championships in his home country. The local hero was also able to win the jump in the second individual combined competition. However, he had to admit defeat to Marjan Jelenko and Johannes Rydzek in cross-country skiing over the 5 kilometer distance and won his third bronze medal within three days.
After the 2010/11 season he announced his move to the special jumpers. However, he will continue to train with the combiners. As in the previous year, Nurmsalu won the gold medal in the individual at the Estonian Ski Jumping Championships in 2011 . Nurmsalu showed good results even before the start of the 2011/12 season. He finished third at the Continental Cup in Klingenthal. In his first World Cup competition at the start of the 2011/12 season in Kuusamo, he qualified for the first round of the 50 best athletes and finished in 43rd place. At the Ski Flying World Championships 2012 in Vikersund, he set a new Estonian record with 204.0 m . On September 8, 2012, he achieved the third success in a row at the Estonian championships. In the 2012/13 season he reached the second round of a World Cup competition for the first time in ski flying in Oberstdorf. After the second round, he finished 26th and scored his first World Cup points. He achieved further successes at the Nordic World Ski Championships 2013 in Val di Fiemme . He reached the second round from the normal hill as well as from the large hill and finished in 26th place. He achieved his best placement with a 13th place in the ski flying of Planica. At the end of the season he finished 49th overall with 40 points.
At the ski jumping at Holmenkollen in Oslo in 2014, he reached sixth place. Only a few months later, on June 4, 2014, Nurmsalu announced the end of his active ski jumping career. The reason for the decision is the lack of financial resources.
On January 13, 2017, he made his comeback after almost three years in the qualification for the World Cup jumping in Wisła . After this two 30th places (in Oberstdorf and Pyeongchang ) were his best results. In June 2017, Nurmsalu announced that he would end his career for health reasons.