A marathon course runs 26.2 miles along an open road. Much tougher to secure than an arena with doors and walls.
Yet across the U.S. and around the world, from West Bend, Wis., and London this weekend, to Nashville, Tenn., next week and Copenhagen next month, organizers of road races are trying to figure out how to improve security after the Boston Marathon bombings.
Paris Marathon director Joel Laine, whose race was held earlier this month, put it this way Tuesday: "There will be a 'before' and 'after-Boston'" from now on.
Still, with thousands — and sometimes hundreds of thousands — of spectators and entrants scattered along the route, there are limits to how much can be done to protect everyone, marathon officials, experts and runners cautioned. They spoke in dozens of interviews with the AP a day after a pair of bombs went off seconds apart near the finish line in Boston, killing three people, including an 8-year-old boy, and injuring more than 170 others.
"This is what everyone thought might happen" following the 9/11 attacks, said Tom Derderian, coach of the Greater Boston Track Club and author of a book about the Boston Marathon.
"This is a 26-mile foot race. With both sides of the street, that's 52 miles to secure," Derderian said. "How? You can't have everyone go through metal detectors."
Marathons aren't just for elite athletes: They have steadily increased in popularity among recreational runners and those raising money for charity. In the aftermath of Monday's attack, which President Barack Obama called an act of terrorism, some marathons heard from runners wondering whether races would be canceled. Yet nearly 40 events, all over the globe, are set for this weekend alone — including Hamburg, Belgrade, Salt Lake City, Lansing, Mich., and the Jersey Shore. There was no indication that any would be called off.
Scott Dickey, CEO of Competitor Group Inc., which manages more than 35 marathons and half marathons around the world, said he's "been in deep conversations already" with the FBI and government agencies "to talk about enhancing security protocol and personnel" for the St. Jude Country Music Marathon and Half Marathon in Nashville on April 27.
"What we're going to do with yesterday's event is we're going to learn from it, and we're going to increase, certainly in the near term and probably permanently, the number of security personnel, both private and public, at our start lines and finish lines," Dickey said. "We're going to review the protocol and procedures that are in place and enhance and improve them so that we're in a better position to prevent these types of tragedies from taking place."
Susie Smisek, director of September's Omaha Marathon, said Boston does, indeed, change the way race organizers go about their job now.
"We'll make sure we have more security available, that people are more aware and are aware of their surroundings," Smisek said. "Will it make us more vigilant in what we do? You bet."
According to Running USA's website, 487,000 runners finished marathons in the U.S. in 2012. A record 30 marathons worldwide had more than 10,000 finishers apiece in 2012, led by Chicago with more than 37,000, followed by London with more than 36,000.
The Honolulu Marathon ranked seventh on that list with just over 24,000.
"You can't plan to stop everything, but certainly everyone will look at tightening things up, for sure. You have to strike some balances between what is feasible and what is possible and what is necessary," said Jim Barahal, president of December's Honolulu race. "It's going to have effects outside the marathon world, which in reality is a pretty low-profile world. It can happen anywhere, at any time."
Lou Marciani, director of the National Center for Spectator Sports Safety and Security at The University of Southern Mississippi, said there has been a lot of progress since 9/11 — especially when working to secure stadiums. But large, public events are especially vulnerable. He said the international flavor of the Boston Marathon could have been a factor in its appeal to the attackers.
"It's very logical," Marciani said. "If you're going to do something evil, and you can't get into something like a stadium, you're going to think outside the box. They went for the soft target."
He expects tighter security at all major sporting events in the coming months — and, yes, there were increased police at baseball stadiums and NHL arenas by Monday night — but a targeted plan won't be developed until a full report comes from Boston.
No matter what law enforcement determines about Boston, Marciani expects start and finish lines at marathons to get the heaviest attention.
That's going to be the case for the 275 or so runners who will participate in the Adrenaline Marathon and other races Sunday in West Bend, Wis., according to organizer Mary Simon. There will be more bag checks there, too. Simon was pleased to see about 20 additional runners register in the aftermath of Boston's bombing.
"One of the great things about these marathons is that they are free and are available to the public. That's why we have hundreds and thousands of people come out and watch them. I can't see how that is going to change. It's part of the whole ethos of what a mass-participation marathon is about," said Nick Bitel, chief executive of the London Marathon.
"What one has to do is make appropriate and reasonable security measures in light of the threats," he added, "and that's what we'll be doing on Sunday."