If Aaron Wallen's training log was a library book, it would be filed under "intense" and cross-referenced under "insane."

That's fine with Wallen. He's a triathlete in training for his sport's biggest stage — the Ironman World Championship in Kona. Accepting questions about his sanity is just as important as accepting pain.

"The ones that are inspired are athletes themselves," he said. "The ones who think you are crazy are couch potatoes."

It's easy to understand why.

To prepare for the race Saturday, Wallen has pushed his body through hundreds of miles of running, biking and swimming.

Some days, a workout can last seven hours. And some days, it will really, really hurt. That's when Wallen will wonder if he's crazy.

He won't stop, though. He knows the consequences of stopping.

"If you quit, no way will you make it through an Ironman," he said. "If you quit once, it will be easier to quit if you are having a bad day. You will be tempted."

But Wallen, who finished the Kona Ironman in 1994 and 1995, is also racing for something other than personal glory — he expects to finish in the middle of the pack.

For this Ironman, Wallen is using the race to raise awareness and donations for Make-A-Wish Hawai'i. As a former member of the Make-A-Wish Hawai'i board, Wallen said, he understands the happiness the organization can bring to an ill child.

So far, pledges total nearly $37,000 — about enough money to provide six "wishes" for children suffering from life-threatening illnesses.

The 36-year-old owner of Haas Insulation Co. has always viewed the Ironman as extreme. It was the lure that hooked him when he was a boy watching it on TV.

"At the time, it was considered the toughest, most excruciating test there was," he said. "I was just so amazed that there were people out there who could do something like that. I thought to myself, one day I am going to do that."

Wallen grew up in Mo'ili'ili and Hawai'i Kai, attending Saint Louis School and the University of Hawai'i-Manoa. In high school, he wrestled. The sport gave him the tools to finish an Ironman, he said.

"I think it gave me the mental toughness to get through these long workouts," he said. "I guess you have to be somewhat sadistic or masochistic to wrestle. And maybe to do the Ironman, too."

Even though he quit the Ironman scene in 1995, Wallen continued to run and swim regularly. He also ran the Honolulu Marathon five times. His Ironman comeback started in February 2006.

"After my second Ironman, I had just finished school and got married, and I needed to basically concentrate on my career," he said. "There was no time for training and competing, so I gave it up. But I knew at some point in time I would come back to see if I had anything still left."

Wallen is confident he'll finish. But how he'll feel at the end "is another story."

"It's a very long day," he said. "It's a very, very long day."

AARON WALLEN

Age: 36

Profession: Owner, Haas Insulation Co.

Residence: Manoa

Height: 6 feet

Weight: 160 pounds

Workout habits: Peak weekly training for the Ironman triathlon in Kona will include 50 to 60 miles of running, 250 to 300 miles of bicycling and 9,000 yards of swimming. Also, regular Pilates sessions.

Long-distance doubts: "All the time. Usually it's the days when I just have no spring in the step. The gears feel a lot harder than they usually do. Those are the days when it is real windy and you are going slow and you just feel like all your strength is gone and you are demoralized. Really, it's just a sign you need a break."

Reach Mike Gordon at mgordon@honoluluadvertiser.com.