Matintalo broke the national age-13 record in the 1000 metres in 2009 with her time of 3:01.01; the following year, she set age group records in both the 600 metres (1:34.21) and 1000 metres (2:58.51).[1] In 2011, as a 14-year-old, she won silver in the 800 metres at the national senior championships; she improved her personal best by almost six seconds to 2:05.87, which was a national under-16 and under-18 record and the best time in the world by an under-16 runner that year.[2][3] Matintalo won silver again in 2012 (2:07.43) before winning her only individual national title in 2013.[1] She represented Finland in the women's 800 metres at the 2012 World Junior Championships in Barcelona but was eliminated in the heats; at the 2013 World Youth Championships in Donetsk, she survived the heats but went out in the semifinals.[1]
Matintalo's development as a runner stagnated early, a problem exacerbated by injuries; she never improved her 800-meter personal best from 2011.[3][4][5] In 2016, she decided to drop athletics and concentrate solely on her other sport, cross-country skiing; the injuries and lack of improvement, as well as Finland's strong skiing team and high-level skiing tradition, were all factors in this choice.[4][5]
Skiing career
Matintalo was a talented skier from an early age; as a youth, her training programs for skiing and running were compatible and supported each other.[6] She represented Finland in cross-country skiing at the 2013 European Youth Olympic Winter Festival in Brașov, placing eighth in the 5 km classical race.[7][8] In 2015, she competed in the World Junior Championships in Almaty, where she placed 16th in the under-20 skiathlon.[9]
At higher levels, the increasing incompatibility of skiing training and running training made it impossible for Matintalo to continue to seriously pursue both sports indefinitely; as a skier, she needed much more upper-body strength, implying additional mass that would slow her down as a runner.[7] In 2016, she decided to continue skiing at the cost of athletics; she moved from her hometown, Pöytyä in southwestern Finland, to Rovaniemi in the north for better training conditions.[4] The move paid off, as she had a good 2016–17 season; at the 2017 World Junior Championships in Park City she won silver in the under-23 women's skiathlon despite skiing with an injured ankle.[5][10]
In the years since, Matintalo has made steady progress toward the top, particularly in competitions held in the classical style, with a handful of placements in the Top 10 in individual and team events. She won her first senior World Championship medal in the women's relay in the 2021 WCH in Oberstdorf, Germany, where the Finnish team (Matintalo, Jasmi Joensuu, Riitta-Liisa Roponen and Krista Pärmäkoski) somewhat unexpectedly seized the bronze medal ahead of competitors such as the United States, Germany, and Sweden.
In the 2021-22 season, Matintalo was in particularly good form in classic sprint events, reaching 4th place (at that point her career best) in Ruka and a 3rd place in Oberstdorf, her first individual podium. She also reached her career-best placements in the overall World Cup and the discipline cups. At the 2022 Winter Olympics, Matintalo skied the second leg for Finland in the 4 x 5 kilometre relay; the team lost the bronze medal by only .5 seconds. In March 2024, Johanna claimed another individual podium finishing 2nd in Falun. Kerttu Niskanen won the race in Falun rewriting history together with Johanna: it had been 16 since two Finnish skiers last received gold and silver medals in the World Cup.
Matintalo is in a relationship with fellow Finnish cross-country skier Lauri Vuorinen. At the 2021/22 season finale in Falun, the couple took the rare opportunity to compete together in a World Cup event when they took part in the mixed team sprint test event, finishing 11th.