Described as one of the “gnarliest” foot races in the southern hemisphere, the Down Under 135 bared its teeth at the weekend to athletes brave enough to have a crack.

The ultra running event was held along the Lerderderg and Wombat tracks near Bacchus Marsh from May 3 to 5, and comprised of a single stage 217-kilometre race along uneven and treacherous terrain. Entrants were required to complete the course inside 54 hours to officially finish.

Of the 32 competitors who took to the course on Friday morning, nine completed the challenge in time.

The event was started in 2017 by four local friends who wanted to create a physical test in their own backyard.

One of the organisers, Dale Chircop, said such events were about testing your limits.

“It’s about the challenge,” he said. “The race itself is over 9500 metres gained, which is more than Mt Everest, so it’s a big sense of adventure. It’s not like running on roads or groomed trails – you do a lot of off-trail stuff, and it does push people to their limits.

“Sometimes it does break them, but most do want to come back.”

Event entries have almost doubled in its short history, with 17 competitors (five finishers) in the first year and the cap of 40 expected to be reached in the coming years.

“It has been touted as one of the toughest ultra-running races on the planet,” Mr Chircop said. “Some guys don’t sleep, some guys have a crew and others go solo … it’s about how much you want to push yourself to complete it in the time allowed.”