Did you know playing frisbee isn’t just something to do with your dog?

To some, throwing a frisbee is a leisure activity one does on summer afternoons at the park.

To others, using a frisbee to play catch with their dog serves as an outlet to release some of their pet’s energy.

Then there are the professionals. Yes, professional frisbee players who compete on 30-player teams from May through August in the hopes of becoming American Ultimate Disc League champions.

Twenty-five teams across the United States and in Canada play in the AUDL, including the Chicago Union.

‘‘People ask me what my hobbies are, and I joke that I have no hobbies,’’ Union captain Pawel Janas said. ‘‘I throw a frisbee for fun. That’s my social circle and my personal life.’’

Janas has been playing frisbee competitively since he was about 12, he estimates, when a childhood friend’s mother took them to one of her ultimate frisbee games. Growing up in Boulder, Colorado, it was a popular sport to get into.

Janas played for the club team when he got to high school and eventually played in college at the University of Colorado. He wasn’t on scholarship to play frisbee, but it ultimately became part of his identity, he said.

After graduating and moving to Chicago to pursue his Ph.D. in economics at Northwestern, the passion he had developed playing frisbee led him to the AUDL.

The league was founded in 2012 and is comprised of four divisions: East, Central, South and West. Each division has at least five teams. The Union is in the Central Division, along with the Indianapolis AlleyCats, the Minnesota Wind Chill, the Madison Rascals, the Detroit Mechanix and the Pittsburgh Thunderbirds.

The AUDL field is similar to a football field, except that it’s 80 yards long and its end zones are 20 yards deep. Each team has seven starting players, and scoring is a lot like football or rugby. In ultimate frisbee, however, you can’t run with the disc in your hand.

Players in the AUDL are paid on a team-by-team basis, but Janas estimates he has spent roughly $30,000 to play — dating to his time in college — and made nothing during his career.

‘‘The biggest expense in AUDL is travel, and we don’t have to worry about that,’’ he said. ‘‘So we don’t get paid, but we don’t have to pay, either [like in club leagues].’’

The Union has one woman on its coaching staff, Sara Gnolek, and Janas says women have made AUDL rosters despite it being a men’s league. The Union is holding open tryouts Saturday at Lane Tech, and Janas, head coach Dave Woods and a handful of other long-term players will be out to scout talent.

Janas is finishing up his Ph.D. and has accepted a job as a professor at Cal Tech in Pasadena, California. Still, he sees an extensive future in ultimate frisbee.

‘‘Eventually, I want to go into a general manager or ownership position,’’ Janas said. ‘‘Even as I pursue being a professor and a scholar, I want to be involved in the AUDL. I don’t see anything happening that would change that course for me.’’