A STRESS fracture and dehydration won't be enough to stop Tim Blair and Shane Taylor from making it to Bondi.

The pair managed to run into Holbrook, New South Wales, yesterday, clicking over the 310 kilometre mark.

Arguably the toughest day so far, the pair started at 4.30am yesterday from Wangaratta.

The freezing conditions didn't slow them down despite struggling to warm up.

However, at the 40 kilometre mark, Mr Blair started to limp.

Over the next few kilometres it got worse and the lower part of his left leg started to swell.

A quick call to his doctor in Burnie gave him a diagnosis of a stress fracture.

This didn't stop the pair from powering through another 86 kilometres before calling it a day to get some treatment.

"Today has been tough," Mr Blair said.

"It started off freezing and then at the 40 kilometre mark my left leg started to become really sore.

"My phone-a-doctor back in Tasmania said it was a possible stress fracture, but you don't worry about that."

It wasn't plain sailing for Mr Taylor either. After finishing the run he started to develop a fever.

Dehydration was the likely culprit with Mr Taylor in bed before 5pm after warming up.

Today the runners have had to change their route and will run to Wagga Wagga before tracking left to their stop over at Gundagai.

After a look over the map the decision was made after there weren't enough roads following the Hume Highway.