Why?

Why would anyone run 26.2 miles? Why would anyone voluntarily pay money to labor through a three- to six-hour endeavor that induces varying degrees of agony and confers no reward other than a medal dangling from a ribbon?

The question was posed at the finish line of Sunday’s 11th annual ING Miami Marathon, which runners crossed with euphoric grimaces on twisted, sweat-soaked faces.

Waiting for them as they checked their times: bottles of water. And a fleet of wheelchairs.

“Marathoning is an insane way to keep your sanity,” said Maritza Baez of Shorecrest. At Mile 23, the toes of her right foot curled into a claw. The cramp migrated to her thigh, then her left hip. She kept going with a limping gait.

Some staggered like drunks. Some made the sign of the cross, bent over, sank to the curb. There were hugs, tears, primal screams. The unlucky or unprepared ones were consoled by medical personnel and whisked to the big white tent full of gurneys and IVs.

Fun, huh?

“It’s addictive,” Darryl Gilbert said. “It’s like fishing. You throw the bait in and hope your next catch will be a big one. You try to beat yourself.”

Gilbert, who works in law enforcement, completed an Ironman triathlon in Cozumel despite ripping up his foot on coral during the swim and sheering off leg skin in a bike crash.

“There was no question that I would finish,” he said, applying ice to an abused knee. “You say, ‘I can survive this.’ The pain part helps you learn about your inner self.”

‘THE POINT’

Wouldn’t meditation be just as enlightening but a lot less bloody?

“You run through the discomfort — that’s the point,” said Diane Discher, 33, a show horse rider and trainer from Joplin, Mo. She fell hard at Mile 2 and scraped knees, hands, elbows. After four hours, a thick red line had coagulated along her shin. This mishap occurred a month after she was bit in the back of the knee by a dog during a run and had the gash sewn up in the emergency room. Nevertheless, she finished her fifth marathon.

“It gives me a chance to let my mind go blank and my subconscious work out problems,” she said. “It helps me be more empathetic to the aches and pains of my horses.”

But meeting a challenge doesn’t have to cause blisters, does it? One could read the complete works of Shakespeare, or Einstein. Make a million dollars.

Prefer an athletic challenge? How about golf?

“We do as many marathons as we can until we drop dead,” explained Mike Nusblat, a 60-year-old from Stony Point, New York, who finished his 61st marathon of 26.2 miles or more on Sunday wearing a leopard-print jersey. He’s a member of an international club called Marathon Maniacs.

Maniac Steve Zaharoff, an engineer from Vienna, Va., has run 43 marathons and aims to hit 50 this year. The toughest race he’s completed is the Hat Run 50K in Pennsylvania.

“It’s got 10,000 feet of elevation change on single track with hairpin turns, rocks, tree roots, and I did it last year in the pouring rain,” Zaharoff said with the kind of glee normal people would use to describe a five-star meal.

One marathon is rarely enough. Endurance athletes keep pushing the envelope. Danielle Furey used the Miami race to prepare for a 156-mile ultra race across the Sahara Desert in April. Furey, a 43-year-old attorney and mother of four from Weston, has done a dozen half or full Ironmans.