It's a muggy August night in Beijing, and Usain Bolt has just conquered the world yet again by claiming a gold medal at the 2015 IAAF World Track & Field Championships.

How does the sprinter celebrate? A brutally cold ice bath in a Beijing hotel room.

"S--t's about to get real," he says, before gingerly submerging his legs into a hotel tub filled with ice water. He winces. More ice is added to the tub.

"This is my celebration," Bolt says, completely deadpan. "More ice. So much fun, right? No it's not."

It's one of the many behind-the-scenes looks at the Jamaican's training routine in I Am Bolt, the new documentary about his astounding career—nine gold medals, eight world records, 11 world championships—and his life as the fastest man in the world. Directed by Gabe and Ben Turner, I Am Bolt offers a rare look at the Jamaican superstar's training routine, alongside the glamorous (cheering fans, national hero status) and not-so-glamorous aspects (ice baths) of being a world-class sprinter.

Bolt's take on the latter? "Listen, man: True champions take ice baths." (Science disagrees—but seeing as Bolt went on to win golds in the 200 and the 4x100, we're not gonna argue with him.)

See I Am Bolt in theaters and Digital HD now, or get it on DVD starting December 6.