Herola won at the Winter Youth Olympic Games in 2012 in Innsbruck in Gundersen -competition and the Nordic Junior World Ski Championships 2012 in Turkey's Erzurum each the silver medal in the Gundersen competition with 5-km run. A little later - on March 3, 2012 - he had his first appearance in the World Cup in Lahti , where he missed the points with rank 47. He has been a regular member of the Finnish World Cup team since the 2012/13 season . Herola won the first World Cup points on December 1, 2012 with 22nd place in the Gundersen competition in Kuusamo , which, together with 22nd place in Lahti in March 2013, also meant his best individual result of the season. At the Nordic Junior World Ski Championships 2013 in Liberec in January , Herola missed the podium by one place in both individual competitions with fourth place. In February 2013 he was also a member of the Finnish team at the Nordic World Ski Championships 2013 in Val di Fiemme . There Herola reached the ranks 22 and 27 in the individual competitions and was eighth in the relay and eleventh in the team sprint. In the 2013/14 season , on January 17, 2014 in Seefeld, he achieved a top ten result in singles for the first time in his World Cup career with tenth place in the Gundersen competition. Two weeks later he won a silver medal at the Nordic Junior World Ski Championships in 2014, as in 2012; this time in the Gundersen competition with 10 km cross-country skiing. Herola also took part in the individual competitions of the Olympic Winter Games in Sochi in February 2014 and finished 16th in the Gundersen competition on the normal hill and 14th on the large hill . Herola finished the season in 22nd place in the overall World Cup ranking.
In August and September 2015 Herola improved his best overall result in the Summer Grand Prix to 8th place.
His first victory in an individual competition in the Continental Cup was in January 2016 in Ruka, Finland, over 10 km Gundersen; a success he was able to repeat over the same route the following day. In the first Gundersen individual competition of the 2015/16 World Cup season in Lillehammer , Norway , Herola achieved his first podium finish in the World Cup with third place. The two victories in the Continental Cup and third place in the first World Cup competition secured him a regular place in the World Cup and in the final accounts of the 2015/16 season he finished in a respectable tenth place overall. On April 2, 2016, Ilkka won the Finnish national championship title for the fourth time in a row.
In the World Cup season 2016/17 Herola reached although never the podium, but was able to prove with consistently good performances in seventh place in the standings. At the 2017 World Championships in Lahti , he was seventh in the team sprint with Eero Hirvonen , and fifth in the team with Leevi Mutru , Hirvonen and Hannu Manninen . In the individual competitions, Herola took twelfth place on the normal hill and 17th place on the large hill. In summer 2017, he placed on the podium for the first time in a Grand Prix competition in Tschagguns . He was able to confirm this performance in the World Cup in January 2018 when he finished third both in the individual and in the team in Chaux-Neuve at the weekend . At the 2018 Olympic Games , Herola achieved his best individual result with eighth place on the normal hill and eight days later he was sixth with the team on the large hill.
When Grand Prix in 2018 won Herola in Villach first time a competition in summer. He finished the overall ranking of the Grand Prix in second place behind Mario Seidl . In the 2018/19 World Cup season , Herola first had to struggle with his form, so that his jumping performance in particular prevented better placements. At the end of the season he was able to improve significantly and achieved second place in Klingenthal, his best World Cup result to date, which he was to repeat in Oslo at the beginning of March . On February 9, 2019, he won a World Cup competition for the first time in the team sprint in Lahti together with Eero Hirvonen. At the 2019 World Championships , Herola took fifth place on the normal hill in both the individual and the relay. In the Gundersen competition on the large hill, he finished eleventh and even with seventh place in the team sprint with Hirvonen, he was unable to confirm the performances from Lahti.
Since the 2017/18 season, the FIS has been compiling a ranking of the best runners and jumpers in addition to the overall World Cup ranking, which clearly shows that cross-country skiing is the Herolas' favorite discipline. While he was second-best in 2017/18 and third-best runner a year later, he was only 30th in the jump classification in both seasons. In winter 2019/20 he won the running championship.
Finland
Villach
2014 Sochi
2018 Pyeongchang
2013 Val die Fiemme
2015 Falun
