"I ordered the classic spaghetti and meatballs to carb load to fuel load for, you know, tomorrow," said Rosanne Myers of Lancaster, Pa.
Some 30,000 are expected to run the Philadelphia Marathon, and 60,000 more to cheer them on.
For some - the event is their first.
"I just wanted to do the experience, and I heard it's a great course," said Curt Hersey of Lancaster.
Meesoud Messkoub of Morristown, New Jersey, can testify to that. He and friends are celebrating his 70th marathon just days before his 70th birthday.
"I started in 2002 right here in this town, and I run all states in the country," said Messkoub.
Security along the route is expected to be tight. The marathon course will be closed at 2 a.m. Sunday. Cars parked along the route have to be moved by then or they'll be towed.
The city released the following information regarding planned closures:
For security, runners will be given clear, plastic bags to carry belongings.
At the Health & Fitness Expo, some runners say in the wake of the Paris attacks, security is a concern.
"For a brief moment, but I'm still going to run," said Annette Richard of Carlisele, Massachusetts. "I'm not gonna let that impede my forward progress."
"The race has been well run the last few years, and I don't think there's anything to be concerned about with everyone being on high alert," said Jeff Shurilla of Ambler, Pa.
But for now their thoughts are on the finish line.
"I expect to be very tired, but I expect to cross the finish line with a smile," said Hersey.