THE second F45 Mackay eight-week challenge has wrapped up and a couple has stolen the show, taking out first place in the male and female category.

By each other's side every step of the way, Oden Frost, 26, and Gillian Turner, 30, kept each other focused and on track to achieve the same goal together.

Through tough self discipline and each other's support, the power couple lost 19.4kg (Oden 11.5kg and Gill 7.9kg) of weight, winning overall biggest transformation.

They admit it was hard to keep off the doughnuts but they didn't slip up once with their diets and always trained six times a week.

"On the first week, I remember I went to the fridge and there was all this leftover bad food from morning tea, I picked something up and I put it back in. I'm like 'nope can't do it',” Gill said.

"My main goal was to get abs and I knew that I had to say no to everything to get abs.”

Gill would message Oden when she was longing for a tasty treat, but he would put the foot down at vulnerable times and vice versa.

She took out second place during the first eight-week challenge, when owner of F45 Mackay Lee Renshaw said she was disappointed, but bounced back and put in 100 per cent this time around.

"She rocked up to every session feeling good, smashed it out every time,” he said. "They followed the nutrition side of things to the exact gram, everything was bang on perfect.

"With Oden, sometimes I went over the road for breaky... he's like yeah I'll come over I'll have water that's it I'll have my one coffee or whatever it may be, that's how strict he was, but that's how strict he needed it to be to get the results he's got.”

Oden agreed it made the challenge easier being in the same household with someone trying to achieve the same goals.

"It definitely drove us more,” he said.

He said the biggest difference this time around was the strictness in nutrition.

Oden is also a trainer at F45 Mackay and has an inspiring success story of his own.

Believe it or not, Oden has lost 50kg in the past four or five years. Hardly recognisable, he said, he had no self control and was in a very dark place before one day the switch flicked in his head.

"That's why you're so determined, because you never want to go back to that point,” he said. "That's why I became a personal trainer.”

Gill said it has been inspiring watching Oden on his weight loss journey and has helped fuel her with determination along her own journey.

One step closer from removing Mackay as Queensland's fattest town, the studio alone shredded a staggering 372.5kg during the challenge.