Kassidy McVey’s legs cramped up in the cold Thursday morning, but she persevered, balancing backward on her hands and feet for two minutes while crab-walking on live television on the Loyola University Maryland quad.

The 19-year-old sophomore helped set the Guinness world record for the most people crab-walking at once — 494 — as TV weatherman Al Roker walked up and down the lines of scuttling students, broadcasting the Baltimore Jesuit university’s school spirit to an estimated audience of more than 4 million on NBC’s “Today” show.

“My hands were numb,” McVey said afterward. “I had to power through. We had to get the record.”

Roker, on the fourth stop of his tour of college campuses attempting world records, was impressed by the Loyola students’ endurance. Crab-walking, as he put it, is “a young person’s sport.”

“These are not slam dunks, these Guinness world records,” Roker said. “These are serious world records. They may seem frivolous — breaking the world record for crab-walking for two minutes. But if you’re going to do it, there’s a certain integrity to the Guinness world record.”

Loyola senior Bob Trosset, who led the effort, initially proposed that the university host the world’s largest crab feast.

School officials signed off on the $6,000 endeavor — a small price to pay for the publicity. But no standing record existed, meaning there was nothing to break on national television.

Guinness World Record officials suggested instead the largest crab walk, a record first set by the Amitie Sports Club of Japan with 279 people in 2013, then topped by Northeastern University with 376 people last September.

Participation at the Loyola event was capped at 500, both for space and to make counting easier. Six participants were eliminated because they didn’t hold the crab-walking pose for the full two minutes, according to Michael Empric, the Guinness world record adjudicator on site.

More than 100 other colleges and universities across the country pitched outrageous records: the largest game of musical chairs, the most people rolling downhill, the biggest pajama party, the most people dressed as Harry Potter, the most dressed as waffles — yes, waffles.

Loyola’s attempt was among the more challenging, Empric said.

“It’s a challenging physical thing to do,” he said. “It’s a great record, and it’s so appropriate for where we are: Baltimore’s known for crabs.”

The mid-size university of about 6,000 students prepared for the event for two weeks. The marketing department and the students spared no efforts. Cheerleaders, an a cappella group, the ukelele club, and hundreds of screaming crab-walk participants and spectators packed the quad for the television spectacle. Many made signs or held up cutouts of Roker’s face.

As he stood in the cold, clutching a cup of coffee, Loyola’s president, the Rev. Brian Linnane, noted the event’s important timing — roughly a month before high school seniors must make their college decisions.

“In the weeks when kids are making their college decisions — it’s a May 1 deadline, so they have a couple weeks — it shows a lot of school spirit,” Linnane said.

Baltimore Sun reporter Tim Prudente contributed to this article.

cmcampbell@baltsun.com

twitter: @cmcampbell6