[5][6][7] Running for Waukesha West High School, Erik won the 800m at the 2008 WIAA Wisconsin State Meet.

Strategically following Duane and the unrelated Jarrin Solomon into the final turn, Sowinski then launched one powerful sprint to the finish, not only winning the prestigious race, but taking the American record in 1:15.61.

[9] Three weeks later, he won the 800 metres at the USA Indoor Track and Field Championships, winning in 1:47.09 ahead of a late charge by Robby Andrews.

[17] In 2019, Sowinski was also a part of the pacing effort, along with Christian Harrison and Harun Abda, which led to Yomif Kejelcha breaking the Indoor Mile World Record.

On February 17, 2022, Erik paced Olympic Champion Jakob Ingebrigtsen to a new Indoor World Record of 3:30.60.