A 23-year-old man from England did not expect to go viral for what happened after his charity endurance challenge, but the harrowing aftermath of his 24-hour treadmill run has now shocked millions of viewers on TikTok.

“I am all fine now, there may still be some problems with my knee but it feels fine and I can now run on it again,” Joe Pritchard, who was raising money for motor neuron disease, told Newsweek. “Surprisingly I’m not mentally scarred from the run but I won’t be touching a treadmill any time soon.”

Pritchard had undertaken a full-day treadmill challenge to raise funds for My Name’5 Doddie, a charity dedicated to finding a cure for motor neuron disease. Though he completed the run to massive support, it was the physical collapse that followed that seized the internet’s attention—and spurred fresh donations.

Pritchard shared a clip of the aftermath to TikTok under @milepie on March 26.

“What happened to me after the 24 hour run,” he told viewers.

The video, now viewed more than 7.6 million times and liked over 447,000 times, opens with Pritchard disembarking the treadmill with the help of his friends, and walking stiffly while clutching his chest.

In a voiceover, Pritchard narrated his experience: “Initially I felt fine, I sat down for like 20 minutes… When I stood up… I couldn’t put any weight on my legs… And I could hardly move them… I felt sick and weird… On the way to the toilet I blacked out, collapsed, vision went…”

Viewers then saw him being supported once again by friends taking him home, where he collapsed for a second time. Eventually, Pritchard took a warm bath and began recovering. Though he is now largely back to health and feeling well, the incident has left lingering questions about the physical toll of such extreme activity, despite its significant moral purpose.

Emergency physician and CrossFit coach Dr. Heather L Hinshelwood provided her insight on this kind of strenuous activity for Newsweek. She warned of several potential risks associated with this kind of physical exertion.

“Being on a treadmill for 24hrs means no sleep and extremely limited oral intake,” Hinshelwood said. “He was at the very least likely dehydrated when he came off the treadmill and could have had some electrolyte abnormalities such as low potassium, magnesium and sodium.”

Hinshelwood also raised concern about rhabdomyolysis, a potentially life-threatening condition in which muscle tissue breaks down rapidly.

“In periods of extreme physical activity, muscle can break down, cause the muscle proteins to spill into the blood,” she added. “This can clog up the kidneys and if untreated can cause kidney failure.”

The 24-hour feat, while grueling, had an unexpected upside.

“It was great to see our video go viral, although it was the more distressing video of the aftermath and not me doing the actual challenge,” Pritchard said. “It’s seen my run reach a much wider audience and off the back of that more people have donated to My Name’5 Doddie and more awareness has been gained.”

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