For the first time in an international championship, Magdalena Stefanowicz competed at the U18 World Championships 2017 in Nairobi . There she reached the finals over 100 meters and won the silver medal in 11.62 seconds behind the Turkish Mizgin Ay . She also took sixth place over 200 meters. She then took part in the 4 x 100 meter relay at the U20 European Championships in Grosseto and was eliminated there with 45.27 seconds in the preliminary round. In 2018 she qualified over 100 meters for the U20 World Championships in Tampere , where she finished fifth in the final with 10.47 s, as well as with the relay with 44.61 s. The following year she was at the U20 European Championships in Borås, Sweden, in 11.62 s fifth and reached sixth in the relay in 44.72 s.
In 2019 and 2020 Stefanowicz was Polish indoor champion in the 4 x 200 meter relay.
Personal bests
100 meters: 11.47 s (0.0 m / s), July 12, 2018 in Tampere
60 meters (hall): 7.32 s, February 10, 2018 in Toruń
200 meters: 24.11 s (+0.3 m / s), May 12, 2018 in Bielsko-Biała
200 meters (hall): 24.08 s on February 10, 2019 in Toruń
Poland
