After seven years of brutal training, Josh Spector, 41, decided to push his body and mind to the absolute limits by running in Brazil 135, an 'ultra marathon' that sees runners pound their way through 135 miles, non-stop.
The folks at Buzzfeed gave Josh a camera to document his experiences - and it has proven to be absolutely riveting stuff.
Speaking about his "addiction" to running, Josh takes us on a journey alongside around 70 other men and women from across the world as they start running in the Caminho da Fé (Walk Of Faith).
He admitted: "I use the longer races as an incentive. It would be hard to justify to myself, to my wife, to my parents, all the weekends, all the mornings, all the time, all the lost sleep, if I wasn't able to say I HAVE to do this. Because I'm running 135 miles."
Check it out:
It's that moment when night falls - and the previously confident Josh loses some of his steely resolve - that really got to us.
“I was very much alone. It wasn’t scary, it was eerie and quiet and time seemed to go much more slowly.
"It would be very easy to stop running."
But Josh knew that, once the sun came up, he would feel differently. Which was true; but while he was in a better state mentally, he was suffering - his feet had begun to blister incredibly.
Josh finished the run in 32 hours 49 minutes and 20 seconds. It took five weeks for his body to recover, it took even longer for his blisters to heal.
But, mentally, Josh felt amazing.
"I do it because I love it."