At 3.45pm on a humid Sydney Thursday afternoon, endurance runner Nedd Brockmann took his first steps in a long, arduous 1600-kilometre journey during which he will try to run four marathons a day for 10 days.

The 24-year-old electrician from Forbes became an online sensation two years ago when he ran the breadth of Australia, from Perth’s Cottesloe to Bondi Beach, in a record 46 days and 12 hours.

That trip saw Brockman clock up an astonishing 3953 kilometres. This time he has set himself the daunting challenge feat of covering 1610km between October 3 to October 13, which equates to 403 laps a day at the Sydney Olympic Park Athletic Centre, where he is attempting to beat the current Guinness World Record set 35 years ago by Greek ultra-marathon runner Yiannis Kouros, who did it in 10 days, 10 hours, 30 minutes and 36 seconds.

Brockmann, who will aim to run for about 16 hours a day, announced the challenge on Instagram in May “We only get one chance at this life and I’d hate to die wondering,” he wrote. “There’s no turning back now, the fun is just about to start.”

So how does Brockmann stay in the zone for that length of time? James Ward, his support team leader, said there was no trick beyond completely blocking out all forms of mental stimulation, such as listening to music, until those desperate times when “he needs it the most”.

“He won’t have music, he won’t have podcasts or anything, and then later in the run he’ll reward himself with that to make it a bit easier,” Ward said.

Asked why Brockmann was attempting the feat in the first place, Ward said he was interested in learning where his true limits lay.

“He doesn’t sit there and go, ‘I love running,’ but he loves the state it puts him in when he pushes himself to the limit,” Ward said. “He is confident that he’s going to have a red-hot crack.”