The thought of running 100 miles is simply incomprehensible for many of us.
Running is one of the most common forms of exercise around the world, but most people set themselves the target of taking of a park run, 10k or perhaps even a marathon.
Literally running 100 miles or 160 kilometres, however, is a feat reserved for the very fittest of us and only those with lungs of steel can stomach such a brutal distance.
Nevertheless, there is a world record for everything these days and the 100-mile run is absolutely no different with Zach Bitter having crowned himself as the latest holder.
The Wisconsin native has been attempting the world record almost annually since 2013, having shattered the American best that year in a time of 11:40:55.
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New 100-mile world record
However, he has now gone one better by astonishingly running 100 miles in 11 hours, 19 minutes and 13 seconds as part of Milwaukee's Six Days in the Dome event.
That means that he was averaging a pace of almost 6:47 minutes per mile, four marathons at around 2:58 hour pace and 402 laps of an athletics track in an average of 1:40 minutes.
It's a simple mind-blowing achievement and completely obliterated the world record of 11:28:03 - set by Russian Oleg Kharitonov in 2002 - that came before him.
Incredible run from Zach Bitter
What's more, he didn't even stop running when he set the world record and broke another feat for the farthest distance covered in 12 hours at 104.8 miles.
“Around 50 miles, I wasn’t super confident that I could double back on that,” Bitter informed RunnersWorld.
“I had a few good laps after that, and when I got to the distance of my longest long run, I got into a really good headspace.
"It was the mental break I needed to stop thinking about the last dozens of miles as a 100-miler, and think of it as something I do on the weekends.
“It was a huge weight off my shoulders. It’s been a huge part of my training for six years, so when I got through it, it was like finally putting the last puzzle piece together.
“Aside from getting the record myself, I hope this put a spotlight on these events. Trails get all the love, but legends of ultras weren’t afraid to take on flatter courses, so if I can motivate some to take a swing at this.
"I think there are definitely guys in this sport who can go under 11 hours. I’m curious to see what the human body can do in this sort of race.”
We're sure that Bitter will go on to produce some even more incredible times but, for now, he's celebrating with a cheese buffet and is somehow experiencing minimal soreness. Superhuman.News Now - Sport News