In a small 11th story room on the cruise ship Northern Sky operating between Miami and the Bahamas, Michael Wardian ran 50K on a treadmill on Saturday evening in 3:06:24, which he believed to be a world record.

But it wasn’t. A few hours later, Wardian, who’d had difficulty confirming any official existing record, learned via Twitter that a British runner, Paul Navesey, ran a treadmill 50K in 3:05:57 in December.

Wardian didn’t sulk. At 3:02 a.m. on Monday morning, less than 30 hours after completing one 50K, he was back on the treadmill for another record attempt. And this time, he accomplished his goal with a 3:03:56. Near the end, he was sweating so profusely that his drenched fingers couldn’t adjust the pace control on the treadmill.

Wardian was on a cruise operated by Spartan Races, which was staging one of its popular obstacle races on Great Stirrup Cay. He’d been tweeting with Gemma Carter of Great Britain, who was planning a women’s world 50K treadmill attempt, which she accomplished on Friday, running 3:55:28, as Run247 reports.

Wardian told Runner’s World he ran the approximately three-mile Spartan Race, had trouble with several obstacles, and finished out of the top ten. Back on ship, he asked Spartan Races President Joe De Sena about setting up the 50K treadmill attempt.

After changing clothes and grabbing a bite to eat, Wardian was soon running in a room on the ship that was "ridiculously hot," he said. "You can’t open a window." He got slight relief when someone produced a fan 30 minutes into the run. Nonetheless, “I was overheating like crazy," Wardian said. "By the end I was tired, but that was okay, I’d set a record."

Or so he thought.

After sleeping for about two hours, Wardian woke up due to hunger, and checked the Internet. News of his treadmill run had hit social media. In response, Wardian heard from Centurion Running, a UK ultramarathon coaching and retail outlet, about Navesey’s 3:05:57.

"Are you kidding me?" Wardian exclaimed to himself.

He found De Sena at breakfast at 6:30 a.m. Sunday, and told him the news about Navesey.

De Sena responded, "You know what you have to do."

Wardian rested the remainder of Sunday, woke at 2 a.m. Monday, and was back on the treadmill an hour later.

"My left hamstring was a little sore," Wardian said. "I wasn’t sure I was going to be able to do it. I felt it slipping away at 28 miles."

Adding to the challenge was doing the run at sea.

"As the boat would shift in the water, I’d feel like I was running uphill, and then down again after the wave left," Wardian said.

Wardian finished 2:01 under Navesey's record, and 2:28 faster than he'd run in his first attempt.

Wardian is well known for such feats. In addition to straightforward accomplishments such as national titles at 50K and 100K, he has set since-broken marathon records on a treadmill and while pushing a baby stroller.

Perhaps most notable is his ability to recover. He raced 54 times in 2014, including victories at the Big Sur Marathon and the Cowtown 50K and a finish as the first American at the Comrades Marathon in South Africa. In January 2012, Wardian ran 2:21:50 to place 62nd at the U.S. Olympic Marathon Trials in Houston, then ran the Houston Marathon in 2:31:17 the following day. On November 17, 2013, he won the Rock 'n' Roll San Antonio Marathon in the morning in 2:31:19, then placed 10th that evening at the Rock 'n' Roll Las Vegas Marathon.

Wardian's unconventional racing and flair for publicity have netted him a list of sponsorships, including shoe company Hoka One One, that surpasses that of most Olympic runners.

Getting the 50K treadmill record “was really emotional,” said Wardian, whose voice, in an interview 12 hours after his run, betrayed that emotion. "I’ve set records before, but I think it was missing it that first time by such a small margin that affected me."

About his latest record, Wardian said, "It showed people if you don’t succeed the first time, if you’re able to, you can take another crack at it—if you’re a glutton for punishment."