Superhuman tests of endurance are nothing new to Calgary running man Martin Parnell.
But attempting to run the Calgary Marathon in full lacrosse gear in under four hours for childrens' charity Right to Play, may have shown the seemingly limitless man a taste of what mere mortals have to contend with.
In the last 10 years, Parnell has completed hundreds of marathons and ultra-marathons, pedalled across Africa, took part in the world's longest lacrosse game and this spring summited Kilimanajaro in 21 hours, three days after running a marathon.
He is 57-years-old, didn't start running until he was 47, and the engineer by profession has dedicated his life in the past few years to support Right to Play and to inspire others to get off their rear ends and achieve.
But despite his lengthy athletic resume, Parnell tells the Huffington Post Alberta this latest challenge pushed him like no other and although he finished the entire course, he failed to finish under the four hours that Guinness required for a world record.
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"I felt like a human guinea pig because no one had ever attempted wearing all that gear to set a world record," he said.
"I was still on pace to finish under four hours at 38 kilometres but then the wheels fell off. I felt unlike I'd ever felt before and I knew something was wrong."
Parnell says he's clocked his heart's high end rate at 168 beats per minute, but after the 38th kilometre on the Calgary course his rate spiked up to 190 and he saw his legs visually spasm nearly out of control.
The heat from the sunny day and the oven effect of the lacrosse helmet on his head took its toll on Parnell, putting him in a place he'd never been in his 10 years of racing. But despite his heart's dangerous spike and his body's desire for mutiny, Parnell still finished the race in four hours and 18 minutes, only 18 minutes off the mark.
"It was just a tough day at the office but I'm thrilled I did it," he said, adding he will attempt the record again.
"You can control somethings in life and many others you can't and that's okay."
The idea to run the marathon in lacrosse gear came after he helped set the world record for the longest lacrosse game last year.
"It's Canada's national sport... and I already had the gear, so why not?" said Parnell.
In 2010, Parnell raised $320,000 for Right to Play by running 250 marathons in one year.
Following that feat, Parnell has embarked on a new endeavour, Quest for Kids, in which he aims to complete 10 quests in five years in order to raise $1M for Right to Play.
Some of the quests completed include the longest lacrosse game, Kilimanjaro, with the next one being the TransRockies Challenge, which will see Parnell tackle all of this summer's 10 events in the Rockies, including multi-day trail runs and bike rides. Altogether, Parnell will cover 888 race kilometres through rugged Rocky Mountain landscapes.