Senior Meagan Iosca ran hard at Sunday morning’s 32nd annual Marine Corps Marathon, her first experience running such a long, exhausting and rewarding race.

This year’s Marine Corps Marathon, otherwise known as “The People’s Marathon,” started at Arlington Cemetery at 8 a.m. About 30,000 runners from around the world crossed Key Bridge into Georgetown, ran through the National Mall, wound around the Pentagon and finished at the Marine Corps War Memorial.

Iosca ran the race in a little more than four and a half hours. Always an avid jogger, she decided to work toward marathon distance this summer and ran in a half-marathon in September.

“Taking off was incredible because you’re running with servicemen and women, first-time runners – you’re running right by Arlington Cemetery with everyone cheering and screaming and the adrenaline is just incredible,” Iosca said.

Iosca was supported by her parents and several friends.

“Toward the end, the last mile feels absolutely impossible, and then you see the finish line,” Iosca said. “I saw that, and I was so excited I’d made it this far. I didn’t care how sore my legs were when I reached the end.”

The event offers participants the opportunity to raise money for charity organizations. Team Memory Makers, a group formed to raise money for the Alzheimer’s Association, raised about $170,000, according to its Web site.

Metro-goers flooded the trains headed to Arlington beginning at 5 a.m. The Metro opened early on Sunday to accommodate crowds.

“It was like cattle herding to the starting line,” said Kellen McMartin, a race spectator from Denver. “It was hilarious. You didn’t need a map; you just followed the masses.”

McMartin’s mother, an Idaho native, dressed her grown daughter so that she’d be able to find her in the post-race crowds.

“My mom made me wear this shirt,” Kellen McMartin said. “It’s a cowboy riding a potato and it’s bright orange, so that she could find me after the race.”

Fluorescent shirts aside, spectators also kept tabs on their runners by means of text messages. When athletes passed certain mile-markers on the course, the computer chips attached to their shoes cued a text message to be sent to a pre-established phone number, usually one of a friend or family member. The texts detailed how far the athlete had run and also estimated his or her finish time.

EMeRG has provided volunteers for the 26.2 mile run for several years.

“We respond if we see someone down or if someone flags us down, because getting an ambulance into tight spaces doesn’t work out sometimes, especially with so many people around,” said junior Stephen Gerber, an EMeRG volunteer. “You’ve got 30,000 people running around. Someone is probably going to roll their ankle at some point.”

Last year’s event saw multiple cardiac arrests among runners, though Gerber said he saw little more than “boo-boos” as he bicycled his assigned stretch of marathon pavement between Third and 14th streets.