For many, running is a way to lose weight and to maintain some semblance of physical activity in their lives.
For others, it's about the therapeutic benefits of finding runner's high during long trail runs across hills and mountains.
Then you have outliers, whose core reasons for running hundreds of kilometres within days are deeply personal and uncommon.
Take Canberra doctor Chris Wilder, for example. In April he was declared the finisher - the first top placing for him - after running 214km in just over 32 hours at Blue Range Hut.
Most of us live a pretty comfortable life. I work in a hospital so this is a way of developing empathy for my patients.
Chris Wilder
The key word is finisher rather than winner because the race is based on the emerging format of backyard running that involves doing laps of a 6.7km circuit - starting every hour on the hour - until there is one participant left standing, or running in this case.
Dr Wilder's and his fellow competitors' achievements at the event, the inaugural Great Ultra Mediocre Back Yarder (GUMBY) hosted by Ultra Mediocre Runners of Canberra Club - are even more extraordinary when considering the potential of having no one declared as the finisher.
That is, if the final two runners drop out during the same lap.
Rest stops and marquees with food and drinks were provided for runners who finished each lap within the hour.
For the ICU doctor, he said the motivation for him was to feel pain.
"We can all do with a bit more suffering," Dr Wilder said.
"Most of us live a pretty comfortable life. I work in a hospital so this is a way of developing empathy for my patients."
The 33-year-old then took on the 100km Ultra Trail Australia event in the Blue Mountains in May and is now set to tackle the Mirrim Wurnit Back Paddock Ultra in Victoria, another backyard event, in June.
The winner of that will be awarded a "golden ticket entry" to Big Dogs Backyard Ultra in the US.
Mr Wilder said the hardest part of running such distances was the sleep deprivation.
"With GUMBY, as soon as the sun came up, it was pretty rejuvenating. I felt like I just had to hang on," he said.
He said his preparations included "doing loops running the same section of track over and over".
Dr Wilder's advice for anyone keen on getting into ultra running is that it should not be intimidating.
"With any of these ultra distances, the nice thing is that it's not about pace or being fast," he said.
"It's about finding that zone to grind along and get to the finish line.
"There aren't many people trying to win, they're just trying to finish. In this one, I just happen to be the finisher."
While Dr Wilder's achievements are a feat of their own, the record for the backyard format is 502km in 75 hours by Belgian Karel Sabbe in 2020.
Fellow Canberra runner Joe Shevlin had never run more than 21km before he ran 80km in 11 hours during GUMBY.
What's more remarkable was that the 34-year-old, who only got into running eight months ago after doing more power lifting in the gym, sustained a knee injury early in the event.
He said he took up the challenge because he was "pretty keen to see if I can at least get to marathon distance".
"The injury was on the second lap and I was in quite some pain by the fourth lap," he said.
"I couldn't make my joints continue to deal with the pounding, especially with the downhill, it was just brutal."
His resilience to running four times the distance of his previous best was asking himself one question every lap: "How long can I continue to say yes?"
"It was less a test of physical ability and much more of a mental endurance and toughness test," he said.
The construction worker said the reward from going through those difficult tests were all worth it in the end.
His next challenge is the Goulburn Duathlon in July before the Canberra 100km trail run in September.
Former Australian 50km walking champion and club president Matthew Griggs, who finished behind Chris Wilder in at GUMBY, said the number one rule about ultra running for anyone interested in trying was that "you don't have to run all the time".
"You don't have to try to run fast. If you start out slow, you'll end up doing better," he said.
