Corey Phillpott is determined to set a new world record on March 3 - to become the fastest man to run a marathon pulling a 1.4 tonne truck.
British man Ross Edgley completed the World's Strongest Marathon in 19 hours 36 minutes in 2016. Three years later, Justin True from the US knocked two hours off the record.
While Phillpott has his supporters, there are plenty who think he's mad.
"Every single person I talk to or who comments on my photo [on Facebook], says 'what the hell are you doing'. Randoms in the street - they say 'you are crazy'," Phillpott said.
The carpenter by trade, fits training around family life and a full-time job, which means he's often lifting weights from 1am.
The 23-year-old does strength training four times a week and will run at least 40km every second weekend.
He's also practising pulling the 1.4 tonne ute every second weekend around an access road at Jamison Park in Penrith. It's about a 1.5km loop with 7 metres of elevation, so to complete a marathon he'll need to finish 31 laps.
After three months of intense training, the Glenbrook resident has only sustained a broken thumb and a rolled ankle pulling the ute. He's been loading the ute up with tool boxes for training - weighing in at a hefty 1.8 tonnes - but will pull 1.4 tonnes on the day.
Phillpott started running five years ago for weight loss and has lost 40kg. He likes to push himself to the limit.
"I want to do a World's Strongest Marathon to prove myself as an athlete," he said.
The event is also a fundraiser for harm-prevention charity ChildSafe Australia. To donate visit: www.gofundme.com/f/corey039s-fund-for-childsafe-foundation-fund.