Cyprian Mrzygłód first took part in javelin competitions at national level in 2014. In 2015 he qualified for the U18 World Championships in Cali, where he failed with 69.52 m in qualification. He had previously thrown over 70 meters several times during the season. In October he achieved the first throw in a competition over 80 meters with a casting weight of 700 grams. From 2016 he threw with the U20 age group with the final weight of 800 grams. In July he was first Polish U20 champion and then took part in the U20 World Championships in his home country. As third in his qualifying group, he moved into the final, in which he was ninth with 70.48 m. In the course of 2017, his widths improved steadily with the highlight at the U20 European Championships in Grosseto, where he won the gold medal with a new personal best of 80.52 m.
In July 2018 Mrzygłód became the Polish runner-up among adults. In the qualification of the European Championships in Berlin, he set a new record with 83.85 m, with which he moved into the final. In the final a day later he did not come close to this distance and took ninth place overall. In summer 2019 he took part in the U23 European Championships in Gävle, Sweden. In the final he again set a new personal best of 84.97 m, with which he secured the European title.
Poland
Cali
Grosseto
Berlin
Gävle