David Larson insists he got lucky – if you want to call the challenge of trekking, mountain biking and ocean/river kayaking 430 miles through harsh, remote environments in all weather conditions nearly nonstop until completion "lucky."

But the 45-year-old Fresnan says he is just that after being selected as a late replacement for a four-man team set to compete at the XPD Adventure Racing World Championships, scheduled for Oct. 31-Nov. 11 in Tasmania, Australia.

Team Driftwood – led by Bakersfield's Glenn Bland and also featuring San Diego's Travis Fishburn and Manhattan Beach's Brian Sturz – is one of 90 teams from 23 countries around the globe and eight from the U.S. entered in the sixth annual event.

"When [Bland] gave me the invitation, I was unbelievably honored," Larson said. "As a kid growing up watching marathons and the Olympics, you dream of representing your country. And for me, this is representing my country in an endurance event.

"I'm not a pro. I'm just an average Joe who gets to represent my country. I just want to finish it, represent well and come back and have some great stories."

Larson has been chasing his next challenge since taking up running 10 years ago as a way to shed the extra pounds he had put on since his high school wrestling days.

He went from running to lose weight to training for and competing in a marathon. After racing in roughly 30 marathons, the married father of five moved on to ultramarathons and was in training for a 100-mile race in Arizona before joining up with Driftwood.

"They kept finding something longer for me to do," Larson joked.

And now comes his longest race to date, an event where Larson will travel roughly 130 miles on foot, 200 miles on a mountain bike and 100 miles in a kayak, while only stopping for two 45-minute naps a day and one mandatory six-hour rest stop.

The four-member teams, who will navigate the course with a map they won't see until 24 hours before the start of the race, can never be more than 100 meters apart at any time.

"It's going to be fun, but with any endurance event, there will be points where you feel good and points where you feel bad," Larson said. "That's where your teammates come in to help you through your downs and you help them through theirs and you keep moving forward."

The race has a time limit of 9 1/2 days, with the top pro teams expected to finish in about 51/2 days. Team Driftwood hopes to be done in 6 1/2.

Larson said he has been running 40 miles a week while also doing plenty of mountain biking, kayaking and weightlifting to get his body ready for its most grueling challenge yet.

"I feel very fit, and mentally I feel like I am prepared for what will happen," Larson said. "But there is no doubt there will be times during those six-seven days where I question my sanity."