It was identity theft. Not by computer but by tour bus.

The near-fatal accident while cycling in 2009 robbed triathlete John Henderson of who he was, mentally, physically and emotionally. He was known for his adventurous lifestyle, trekking around the world to compete in challenging events and sharing his passion for the outdoors.

Seventeen months later, the 36-year-old is slowly and painfully putting his life back together. No longer able to train for races he so enjoyed — such as Sunday’s XTERRA World Championship on Maui — Henderson is training others to excel as he did.

"I lost everything, really," said Henderson, who was left a paraplegic after being hit from behind by a tour bus while riding on Kamehameha Highway near his Waialua home. "It’s such a paradigm shift, having to go from the totally active me to trying to find a way to still be a part of everything.

"When I was laying in bed and couldn’t move, with my whole left side paralyzed and paralyzed from the belly button down, all I could think was, ‘I’m screwed. What do I do now?’"

Being so fit is what saved his life, according to doctors who had to deal with his 28 injuries, including one to the spinal cord. Having the mental toughness and discipline to train for triathlons and ultramarathons is saving the former Navy diver now.

After months of intense rehab, Henderson has regained some movement. He can swim with flotation aids, do some weight training, even stand some. And he has returned to work — in a wheelchair — as a surgical representative who consults with doctors during procedures.

Henderson is now making the transition from coaching in the operating room to coaching triathletes. His students include Laurel Dudley, his girlfriend of three years, who was riding with Henderson when the accident happened.

"It could have so easily been me instead of him," she said. "I know that if the roles were reversed, there’s no question we’d still be together. We’re so grateful for all that we have.

"The biggest change is we used to spend a lot of time outdoors together. We’re both optimistic people. We WILL do that again."

Henderson and Dudley competed in the 2008 XTERRA, his 12th, her first. Dudley will compete in her second Sunday, with Henderson as support.

"He’s a great coach," she said. "He’s really taught me how to ride. It does make me sad to look at the pictures from that race, but I won’t dwell on that.

"Then I look at the helmet he got at that XTERRA. He was wearing that when he was hit and it saved his life."

A part of Henderson will be competing Sunday. He has loaned his bike to Amy Bennett, whose bike was stolen earlier this month.

"I sent an e-mail out to the mountain bike community, telling them it was stolen and to be on the lookout for it," Bennett said. "Within minutes, people were texting me, saying don’t worry, I’d have a bike to ride.

"John texted me, ‘Come grab my bike. It’s totally race-ready and it needs to go out and play.’ For John to reach out like that captures the whole spirit of XTERRA and how the mountain bike community takes care of each other. And no one on this island has done more to raise awareness of getting out to play in this wonderful place we live than John."

For someone once ranked in the top 10 internationally for offroad triathlons, Henderson is slowly finding his new identity as a coach.

"I realize I have so much to share," he said. "And if I hadn’t had the experiences I had, I wouldn’t be able to do that.

"I’m hoping to do the paralympics, get involved with paddling, and maybe create an adaptive climbing facility. I still don’t know who I’m going to be. I just know it’s a work in progress and we’ll have to see where this path goes."