Kevin Pearce, After the Crash

Kevin Pearce gets help with his balance from his Pilates instructor Emily Stein Anderson at the River Valley Club. Credit: Bill Greene / The Boston Globe / Getty Images

Every day, Kevin Pearce is slammed with another reminder that he's no longer an elite snowboarder. He lives in a house in Southern California that he doesn't remember buying. He sets the alarm on his cellphone four times to remind himself of appointments. And when he hits the slopes, he makes simple runs instead of attempting the big-air tricks that made him one of extreme sports' rising stars.

On the day his life changed, December 31, 2009, Pearce was rivaled only by Shaun White. Known for his teen-idol shag and half-pipe skills, Pearce started snowboarding as a child in Vermont and turned pro in 2005, at 17. Just three years later, he was a shoo-in to make the 2010 U.S. Olympic team. While training for a qualifier in Park City, Utah, that day, something went horribly wrong: He tried pulling a cab double cork – a double backflip with a twist – but caught his toe-side edge on the landing and slammed his face into the wall.

Though he was wearing a helmet, Pearce was knocked unconscious. His left eye socket was broken, and there was bleeding inside his head, the result of his brain being jostled with tremendous force. Pearce spent the next six days in a coma and the following months ­ – and years – struggling with memory loss, vision problems, and mood swings. "My life was so set, like concrete," he says. "And then it flipped upside down."

Pearce's rise, fall, and ongoing recovery are the subject of 'The Crash Reel,' a documentary that debuts on HBO this month. The film begins with grisly footage of the accident and Pearce's subsequent days in a Denver hospital, where he sported a shaved head and the blank expression of a zombie. (At his doctor's suggestion, Pearce's family began filming early on, rightly assuming he wouldn't recall any of that period.) "The first month was day to day," recalls his brother Adam, 28. "He could move a finger, now a hand, now a foot."

As Pearce's condition improved, the family had tense discussions about whether he should ride again – a possibility his neurologists stressed shouldn't even be under consideration. "His brain wasn't telling him he wasn't as good anymore," says Adam. "That was a struggle for us." For Pearce, the footage was revelatory. "I don't remember that we talked about that stuff," he says, "so to go back and watch it was like, 'Whoa.' "

'The Crash Reel' arrives at perhaps the apex of the debate about safety in extreme sports, following the recent deaths of snowmobiler Caleb Moore and freestyle skier Sarah Burke. But Pearce remains unapologetic about the risks action sports athletes take. "We're not being pushed," he says. "There's no coach going, 'Do a triple cork!' We do it because we love it."

Although Pearce, 25, has returned to the slopes, his own days of hardcore tricks are over. "Knowing how fragile my brain is," he says, "it's not worth it." He's done X Games commentary for ESPN and still has deals with companies like Burton, Oakley, and Nike. But his future plans are in limbo. Pia Pearce thinks her son should pursue ping-pong, which he's been playing to improve his hand-eye coordination. However, his therapy is likely to continue for years.

Pearce says he's considering speaking engagements to talk about traumatic brain injury and, by extension, a more universal theme – rebuilding your life and goals when they collapse overnight. "Everyone's thrown a hardball in life, even if it's not a brain injury, and they have to deal with it," Pearce says. "So we're showing people that if you work hard and put your mind to something, anything is possible."