Rebecca Rusch was deep in the insect-infested jungles of Borneo when the cockroaches began to crawl all over her. Or so she thought. Four days spent biking, running, kayaking and climbing—on two hours of sleep a night—had left her hallucinating.

“I tried to take vitamins during the race,” she recalls. “I was dumping out vitamins in my hand and all of a sudden they became cockroaches. I chucked the vitamins and ran around in little circles. All my teammates started laughing at me.

“I didn’t take any more vitamins that race.”

For some people, trying the spicy pho at the Vietnamese noodle house is adventurous. For Rusch, the excitement doesn’t really kick in until she is seeing pigs attacking her bike or one of her teammates is talking to trees.

Rusch is one of the most famous women in the world of adventure racing. In the style made most famous by “Survivor” creator Mark Burnett’s “Eco Challenge,” an adventure race typically covers around 600 miles over five days. The course’s checkpoints are kept secret until the start of the race; to complete the race teams must navigate every type of topography imaginable—river and ravine, mountain and marsh—while staying together and resting just enough to stay clear-headed.

“Each race is kind of a life-changing experience,” Rusch says. “I always want to explore, see a new place...I love reacting to a challenge on the fly, reacting to what’s in front of you.”

This Friday, Rusch will compete with Team Specialized in the Sea Otter Classic’s own brand new adventure race, a special new spoke in a characteristically huge wheel of weekend activities (see event guide, pg. 24). While the half-day sprint won’t scratch the lens of perception like Rusch’s sleep-deprived endeavors, it will allow a wider spectrum of people to delve into the rugged and exciting experience.

“The short stuff is getting really popular,” Rusch says. “The cool thing about Sea Otter is they’re taking this relatively new sport to a huge venue with a ton of cyclists.”

For Rusch, the Sea Otter just fits into an already-packed calendar—the 38-year-old drips competitive adventure from her pores. Since the start of ’06 alone, her various teams have finished sixth at the Adventure Race World Series in Sweden and first at Australia’s top Expedition Adventure Race in Tasmania. Rusch herself claimed championships at the US Solo Mountain Bike Nationals in Wausau, Wisc., the 24-Hour Solo Mountain Bike Race in Spokane, Wash., and took second at the 24-Hour World Championships in Conyers, Georgia.

But when Rusch reports to the Peninsula this weekend, she may not even be the most adventurous athlete on her own four-person team.