The college sports center offers over 1000 different courses every semester, run by over 500 trainers, who are mostly students themselves. Compared to other sport clubs, the Hochschulsport is very affordable and you get to know many other students from different degrees. Some events are even for free.
You can find the entire List of offers on their website. For many of those courses it is necessary to register at the beginning of the semester and pay a small fee. Some courses for example martial arts courses or dancing lessons are very popular and the free places are usually booked up only a few hours after the begin of the registration time, so you need to find out when this registration time starts and sit on your computer at the right day and at the right time - first come - first served.
If you have not booked a course in time that is no reason to quit sports or stay at home. On the one hand side you can use the search option to find free places but on the other side you can also visit one of the many courses which do not require a registration. Definitely the most popular of those is "Fitness mit Musik" which the local students call "Kontakthüpfen" . On Saturdays and Sundays you can do Circle Training for free, without having to register for it.
Moreover the Hochschulsport - Team organizes various annual events. For example the Sports Day in June, a sports show, a football cup and a ball.