After developing an interest in dancing, Polster enrolled at the Royal Ballet School of Antwerp.

[3] He appeared in a number of television commercials and music videos, before making his film debut in Girl, in which he played the role of Lara, a trans girl who pursues a career as a ballerina.

[4] His portrayal received general acclaim from film critics, resulting in numerous accolades.

[5] At the 9th Magritte Awards, Girl received nine nominations and won four, including Best Actor for Polster.

He continues as a guest performer in the same company in the role of Pablo for the piece "Der Steppenwolf" by Goyo Montero and is a dancer in Göteburg.