Trollhättans Simsällskap (swim club) is the organizer and host of the Swedish Youth Championship in swimming where over 600 athletes participate. The competition takes place at Arena Älvhögsborg in the heart of Trollhättan.
The Swedish Youth Championship in swimming is held twice a year. During the summer the races take place on a long course (50m), and during the autumn/winter on a short course
(25 m). SUM-SIM is one of the largest competitions in swimming, with participants from all over the country. In the SUM-SIM competition girls and boys between 13 and 17 years of age are eligible to participate.