With the number of runners for this year's Naperville Marathon doubled to 7,000, plenty of slots remain open as registration nears the end of the first week.
Following pre-registration to run for 26 charities and two days of open registration, race organizers said that just over half the spots for the Nov. 9 race had been grabbed.
"We had a really strong start," race director Bob Hackett said Monday. "When general registration opened at 6 a.m. Saturday, there were 300 people who instantly signed up. We're well ahead of where we thought we would be."
After last year's inaugural race sold out in 14 hours, the city council approved an expansion last month.
The Edward Hospital Naperville Marathon & Half Marathon has been designated a qualifying race for runners wishing to participate in the Boston Marathon. Hackett said about 17 percent of those finishing last year's Naperville event were certified for the Boston race, which this year will be held on April 21.
"The way Boston works is, you have a qualifying time based on your age, and it also varies by gender," Hackett said. "As you get older, the qualifying time for Boston increases. So for some people, you don't have to get faster, you just have to get older."
Hackett said there was little chance they would want to expand the Naperville race to the scale of the Chicago Marathon, which draws some 45,000 runners.
"How much bigger can we get? We'll have to look at this year's race with the 7,000 runners and judge how we perform," Hackett said. "We really have to look at this and execute not just to the expectations of the city, because they're our customer, but also to the runners and the businesses and people in the community. Chicago's will always be a very special race, but we don't have any desire to get that large."
The course for this year's Naperville Marathon will take runners through 26 neighborhoods that include many areas in the city's southwest quadrant. The off-road trails used last year will be omitted for runner safety and in order for emergency vehicles to have better access.
"Even after the race is over, we have to make sure the runners say it was a fun race and that they were proud to run in the Naperville Marathon," Hackett said.