More than 31,000 runners registered for the 40th Honolulu Marathon and each person has a unique reason why.

"Really every person has their story and their reason to run it," said Honolulu Marthon President Jim Barahal.  "And some of them are quite moving and emotional."

Take Julie Weiss of Santa Monica, Calif.  The 41-year-old mother of two ran for her father.

"He's in my heart.  He's the wind at my back.  He's always there smiling," said Weiss.

But, her dad didn't get to see his daughter finish on Sunday or the 37 marathons she has run in the past 37 weeks.

"He passed away in 2010 from pancreatic cancer," said Weiss.  "And I knew I had to do something and it should be centered around my passion for running and the love for my father.  So, here I am running 52 marathons in 52 weeks.

Weiss has already raised more than $100,000 for the Pancreatic Cancer Action Network through her website MarathonGoddess.com.  With 15 marathons to go, she hopes to raise even more.

"I always say reach for the moon, even if you miss you'll land amongst the stars.  My goal is a million dollars," said Weiss.

The goal of organizers in 1973 was to one day hold a race that rivaled the Boston Marathon.  Forty years later, mission accomplished.  This year, the Honolulu Marathon was the second largest in the U.S.

"And we'd like to stay in the top three.  So, we're going to work real hard to keep growing, keep getting better and better," said Barahal.