A large group of people are exercising in what appears to be a gym

A large group of people are exercising in what appears to be a gym. Most of them are standing in rows and throwing large black exercise balls straight up into the air. Many of them are shirtless, while the others are wearing workout clothes. There are several large screens mounted to the wall, displaying timers and scores. There are other people watching the exercise, some of them recording the event with their phones. The gym has high ceilings, black walls, and bright overhead lights. There is also a large electrical box with warning signs attached to a support column.