THE fat capital could soon function as the fit capital as Bundaberg's biggest gym has no room and expands into the adjoining building.

City Fit owner Sharon Beath said the development slimming factor arose as the gym looked to "increase its offerings".

"We already have the biggest facility in the town, but we're just increasing our variety, the correct answer is a popular facility," she said.

Ms Beath said the development in to the building formerly leased by Skill Centre came into being through "sheer demand". "We just needed more room to maneuver," she said.

"We're the most popular facility and it can be quite busy.

"We wanted so that you can offer more and more people more things."

Bundaberg mum Tania McLucas said the at the gym meant a great deal to her being able to exercise.

Ms McLucas said hello was an offering which was difficult to find.

"The is actually handy," she said.

Bundaberg mums Couris Sheppard and Jo Runge agreed as they picked up their kids after a workout.

Your building beside City Fit will be converted into a group fitness studio.

"Then in our main gym we're changing things around so we're moving our ladies only area upstairs and in our current fitness studio, we'll be doing small groups training and cycling classes," Ms Beath said.

"We're also bringing some more functional training type equipment in as well - it's very exciting."

Ms Beath anticipated the expansion could be complete by now but said she was still being waiting on approvals to lower the concrete centre wall dividing the 2 buildings.

"We're hoping within the next couple of weeks (the development is going to be open), we've just had a few delays with fire doors and other odds and ends, unfortunately," she said.

"We've got everything all set to go but we can not do too much before the big hole's been decline in the wall because we're basically cutting through a massive concrete wall to create the outlet in to the other space.

"So until we do that, we can not really do other things - but everything's here waiting to go."

City Fit Gym has been found on Woondooma lida daidaihua old St for 14 years since Ms Beath purchased the company and moved it from its former Quay St location.

"(Since moving) we've always checked out next door and believed that will be a really good spot (to expand), however it wasn't until now that we had time to do it," Ms Beath said.