His adrenaline rushing at the top, former U.S. skier Cody Marshall steeled himself to tackle the daunting course.

Three deep breaths. A quick pep talk. A determined gaze.

Eighteen grueling steps later, he reached the bottom of the stairs at the rehab center — exhausted but as exhilarated as if he conquered a World Cup mountain.

In July 2009, Marshall suffered a traumatic brain injury when he lost his balance sliding down an escalator and toppled over the side, falling about 30 feet.

These numbers still startle him: 50 percent (chance of survival), 10 days (in a coma), two months (hospital recovery time), 16 ½ inches (the wraparound scar on his head).

This empowers him: Another chance. Not to compete — his comeback attempt was cut short — but to coach and help launch a program that prepares skiers for their post-racing careers.

“It was a huge mistake that had big consequences,” Marshall said in a phone interview from Park City, Utah. “But I’m lucky to be here. I always try to remember that.”

The 34-year-old Marshall grew up skiing in Killington, Vermont, and made the national squad in 2007. He was an up-and-comer renowned for his ability to tackle tight turns. He won a pair of NorAm Cup slalom titles and also raced in 20 World Cup competitions, with his best finish 19th during a slalom event in Wengen, Switzerland.

Then, the accident.

He was at a retail center in Park City, hanging out with some buddies when he jumped onto an escalator intending to slide down — something he’s done countless times. He doesn’t remember any of this, though. His recollections are wiped away from about four hours before the accident and 1 1/2 months after.

But this is what he’s pieced together: He leaned back to achieve more speed and simply tumbled over the side.

“They said I was not going to be able to live a productive life and would be in assisted living,” Marshall recounted. “But I kept breaking through those barriers. I kept making a strong recovery.”

He relearned to walk by tackling stairs. Go up a few flights and then ride the elevator back down. One day, he told his physical therapist that if he climbed up, he fully intended head down the same way.

A big step in his road to recovery.

“I was more nervous than I was at Wengen for my second run at a World Cup,” Marshall said. “But it’s one of things I’ll never forget.”

Ever so steadily, Marshall’s strength returned. He even tried to resume his ski racing career.

“I wasn’t willing to take risks that I needed to take, because I didn’t want to hit my head again,” Marshall said. “That’s really why I decided to step away.”

The next chapter of his life? He had no idea.

About that time, he crossed paths with Bob Bennett, a highly successful businessman who was interested in becoming a ski racer and asked Marshall to serve as his coach. As they traveled to races, Marshall overheard Bennett talking about business deals and began asking questions.

“I was like, ‘Hey, Cody I could teach you how to do this,’” Bennett said. “He said, ‘Bring it on.’”

Bennett runs a private equity firm called GroundSwell Resources. He was working on a project to teach people how to build and grow a business in an apprentice-like environment. Marshall became the test subject and was paired with Bryon Friedman. He worked with Friedman’s company, Soul Poles — they makes bamboo ski poles — to help grow his company.

It worked out so well that the project lead to the formation of GroundSwell Athletics , which launched nearly a year ago and is geared toward second-tier sports that don’t receive a lot of financial support. The premise is simple: Athletes train under Marshall — or with their independent teams — and then head into the classroom for business development. There are about a dozen student-athletes enrolled in the program.

A typical day goes something like this: four hours of workouts in the morning, followed by online classwork after that. Currently, they’re developing a strategic plan for a company in the solar-panel industry.

In addition, Marshall coaches two-time Olympian Megan McJames, who’s racing this weekend at U.S. championships in Maine.

“When I was on the national team, it weighed on me quite a bit — I know I’m going to retire at some point. But what am I going to do in my early 30s and I was a really good ski racer but never went to college?” Marshall said. “It’s tough to build career in your 30s. This could help in your next stage in life.”

If not for the accident, Marshall could’ve possibly been the next big name in U.S. skiing. It’s a thought he won’t let cross his mind.

“When I left the hospital, it was a very, very tough time for me,” Marshall said. “It didn’t matter why it happened, or even that it happened. What mattered is that I made progress going forward — that I rebuild my life.”