It’s the largest sporting event in Central Florida, and it is taking place this weekend.

The Walt Disney World Marathon brings 100,000 runners and spectators to Central Florida during what would otherwise be a slow tourism time after the holidays.

Marathon weekend kicked off early Thursday with a 5K race through Epcot.

The races bring runners who are here not only to have a good time but also hoping to help those in need.

Maggie Ryon from Lake County will be running in the full marathon Sunday. She’s running in honor of her 8-year-old son, Jay, who was diagnosed with leukemia two years ago this month.

“My son is in remission, but the chemo is long and almost took his life. It’s nasty and it’s really difficult, so just kind of getting by isn’t good enough. We need a cure,” Ryon said.

Ryon is hoping that cure for blood cancer is possible with funds raised by running in the Walt Disney World Marathon.

So far, with family members, she has helped bring in more than $18,500 for the Leukemia and Lymphoma Society.

“He fights every day, and if he can fight through chemo, I can fight through 26 miles,” Ryon said.

She and her family aren’t alone in helping out.

Runners in the Walt Disney World Marathon have helped raise more than $82 million for the Leukemia and Lymphoma Society over the past 20 years.

Almost 600 runners this weekend are raising money for the organization, such as Debbie Barry and her friends and family from Massachusetts.

“I’m one year in remission for lymphoma, and they’re walking with me for this today, so it’s my first 5K and that’s what we’re here for,” Barry said.

“We have thousands of runners who are running who are running on behalf of charitable organizations. We provide them tools to help them communicate and help them raise their funds,” said Tina Trybus of Disney Sport and Youth.