Dave Proctor, a 35-year-old massage therapist, set two world records on a treadmill between 4 p.m. May 27 and 4 p.m. May 28 at an expo center in Calgary.  

Twelve hours into the run, Proctor had completed 139.2 kilometers, or 86.49 miles, besting the previous 12-hour treadmill record, set in February, by 6.3 kilometers. 

Then he kept going. 

Twelve hours later, he had his second record. In covering 260.4 kilometers (161.81 miles), he outdistanced the mark of 160.24 miles set in 2004. To do so, he had to average about 8:54 per mile. 

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Proctor was part of a team of runners fundraising for MitoCanada, an organization that raises awareness of mitochondrial disease. 

A veteran ultrarunner, Proctor knew the record was within his grasp last December, when he placed sixth in the 24-hour running world championships held in Italy and covered 257.88 kilometers.

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What he hadn’t accounted for was the toll running on a treadmill takes on your mind. 

“The sun doesn’t go down and you don’t move,” he said in an interview with Runner’s World by phone. 

All he could do is glare, with growing annoyance, at a crooked poster on the wall ahead of him. He wanted to straighten it. 

At the beginning of his attempt, things had felt great. 

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The other MitoCanada runners were attempting various treadmill records around him. A crowd gathered, Proctor posed for selfies, and he high-fived supporters. He was, in his own words, “being an idiot.”

His wife cautioned him to conserve his energy. When he didn’t listen, she made a sign that read, “Do not speak to or feed the animal” and hung it from his treadmill. She stayed with him the entire time, however, as did their 10-year-old daughter (who took a four-hour nap). 

At 8 p.m., the expo hall closed. His run became work. Then the building HVAC system shut off, and as night set in, everyone was sweating and overheating. 

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When he passed the 12-hour mark and had the first record, things got even tougher. With still two hours to reach his goal, all he could stomach was Coke. He couldn’t see straight, his ears were ringing, his toes felt numb, and no bathroom run would remedy the turmoil he felt in his stomach.

His friend Blaine Penny, the founder of MitoCanada, talked him through the pain.

Atop his treadmill’s dashboard Proctor had taped pictures of his family to inspire him. He also remembered Penny’s son, Evan, 12, who has suffered from mitochondrial disease for the past nine years. He is currently hospitalized.

Proctor’s own son, Sam, 7, suffers symptoms similar to mitochondrial disease with an undiagnosed disorder that affects his muscle coordination. He requires the aid of a walker to walk. 

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This record was for them.

Together the fathers and the other MitoCanada runners raised $75,000 for the charity. 

“Outside of the birth of my three kids and my marriage this [record run] was the most impactful moment of my life by far,” Proctor said.

This article originally appeared on RunnersWorld.com.