HONOLULU -- Honolulu Marathon week officially kicked off Wednesday with the opening of the Marathon Expo.

Each year, the Honolulu Marathon brings about $100 million in spending and this year, hopes are high for an even bigger economic boost in spending because of the current strength of the Japanese Yen.

About 22,000 people have signed up so far for this year's Honolulu Marathon and just as in other recent years; about 60 percent of the participants are from Japan.

This year, about 15,000 Japanese will run in the Marathon, a few thousand more than last year.

With the Japanese Yen very strong, they are spending happily at the expo on everything from ointments for sore legs to souvenir clothing and even custom fitted ear buds to go with their iPods.

Rei Fujisawa enjoyed shopping with her classmates from Kobe Women's University.

Each year, the marathon hires Hawaii Pacific University students to survey 1,500 out of town participants including a thousand Japanese on their spending.

"I expect an increase in spending particularly from the Japanese due to the fact that the yen is on a 15-year high," said Hawaii Pacific University Professor Jerry Agrusa.

Almost 20 percent of Japanese marathoners surveyed said they'll go to neighbor islands.

"So the impact is not just on Oahu or Honolulu it is also on the neighbor islands as well," said Honolulu Marathon President Dr. Jim Barahal.

Mainland visitors are also caught up in the shopping frenzy.

"With economy being rough, tourism struggling a little, I think more than ever, the marathon is a welcome thing at a great time for Hawaii," said Barahal.

Craig MacBean has run marathons in 49 states and is in Hawaii to do his 50th marathon.

"My wife's over here and she is spending plenty for both of us. So we are spending a fair amount. We are having a nice time," said MacBean.

Some marathoners from the Mainland told the survey team they are foregoing Christmas presents this year and instead spending money on their vacations in Hawaii.

The Honolulu Marathon also helps the economy in other ways by putting more money in pockets of workers employed by the event.

This year, the marathon has hired 484 special-duty police officers to provide security at the expo and on the course.