UPDATE: The personal trainer of a woman who was abused by men who called out "run fatty run" to her says she can hold her own.
Toowoomba woman Rebecca Ruse has publicly challenged the men to a fitness competition.
Mr Gillis owns fitness company Zenon Fitness.
He said Ms Ruse could hold her own.
Ms Ruse is more formidable that she may appear.
She can leg press 340kg and can lift 105kg.
"Rebecca could give anyone a run for their money," he said.
"In the time that I've spent with Bec she's shown constant achievement, development and growth.
"The things she can do when she sets her mind to it are amazing.
"I'm incredibly proud to have Bec as a client and as a friend as well."
He said fat shaming was wrong.
"It's essentially bullying, there's just no need for it.
"You don't know someone's back story and you have no right to abuse them in that way."
He said it was verbal and mental abuse and applauded Ms Ruse for calling the men out.
"We all know exercise is good for anyone at any level - whether you're fit or not."
Mr Gillis said people who were trying to make a change in their lives should be encouraged.
"Why would you go to the gym if you're made to feel like you don't belong?"
EARLIER: It's the kind of abuse that's way too common.
But Toowoomba woman Rebecca Ruse wasn't going to let it fly.
She was working as a delivery driver, and running between jobs, when two men decided to yell abuse at her, taking aim at her weight.
While driving away in an orange Holden Commodore they yelled out "run fatty run" to Ms Ruse.
Instead of backing away, Ms Ruse has publicly challenged the men to a fitness challenge.
"How about you put your money where your mouth is and join me in a training competition," she wrote on a popular car site.
"If you win I will pay for a personal training session with the trainer of your choice at Zenon Fitness.
"If I win you have to make a public apology."
She said if the men weren't too scared, they could accept the challenge by responding to her post.
"Personal message me so we can organise a day and time," she said.
"I will book in the time with my trainer Robert Gillis."
Should the person accept Ms Ruse's challenge?
This poll ended on 05 May 2016.
This is not a scientific poll. The results reflect only the opinions of those who chose to participate.
It could turn into a public spectacle.
"It it goes ahead and people would like to be spectators there will be a small charge and all money will go to Zenon Fitness' preferred breast cancer fund," Ms Ruse said.
Her stand has already attracted supporters in Toowoomba.
Gail Anderson said: "Good on you girlfriend."
"You could have been at home curled up on the couch but no you were out working your butt off.
"Just ignore the people that have no respect."
As yet no-one has accepted the challenge.