WATCH: Norwegian athletes spend 24 hours running laps in a basement

If you’ve ever read about a race or endurance event and asked yourself “why?” this short film is for you. “I love running and can truly understand why people want to challenge themselves both mentally and physically,” says endurance athlete and filmmaker Göran Winblad. Despite that, the Bislett 24-hour Indoor Challenge, held in the basement of the Bislett stadium in Oslo, Norway, left Winblad baffled.

Winblad heads to the event to figure out what motivates the athletes “running in circles with nothing but cement walls to look at.” Arriving at the stadium after the 20th hour, Winblad says he doesn’t know what to expect or if anyone will even be functioning well enough to speak to him.

Watch this short film for the remarkable humans Winblad talks to and the insight they share, but also for Winblad’s stunning filmmaking skills–who would have thought a race in a basement could be beautiful? Frank Løke, who completes 217 km by the end of the event, calls it the “toughest thing he does all year.” But, he adds, it helps him train to summit Everest and K2. “How can you train for the toughest mountain in the world? You have to do some crazy sh*t,” Løke says.

One of Norway’s best ultrarunners, Bjørn Tore Kronen Tarenger (who leads the event with 260 km) calls the monotony and challenge “fun.” (To be fair, he looks like he’s out for a 5K jog in the park.) Winblad asks Tarneger what, exactly, makes the event fun, and Tarenger’s response is what one might expect from someone who enjoys running in circles for 24 hours: “I feel the pain.”

One runner, whose feet are so sore by the time Winblad speaks to her that she’s forced to run “like a penguin,” says she thinks it’s “something you have to do once in a lifetime.” She quickly adds that it’s her second time. Winblad notes that many of the runners say they’ll never do the event again when he speaks to them, yet keep returning year after year–the race sells out in moments.

The Bislett Stadium hosts many renowned track and field events, and Karsten Warholm famously set the world 400m hurdles record there, the drive behind which Wimblad can understand: “fame, money, being the best in the world.”

With an hour left in the event, a shift happens, and watching it from the comfort of your home, you may just find yourself tempted to sign up.