BANGOR, Maine — Chris Young began thinking about owning his own gym when he was a youngster.

His first experience running a gym, Young’s Mixed Martial Arts, began in the basement of his Brewer home in 2009.

“My basement was 600 square feet,” said Young.

On Sept. 5, he will find himself staring at 15,000 square feet of space when he moves Young’s MMA into the Union Street Athletics facility on Griffin Road.

“This has been 10 years in the making, at least,” said Young.

Young will purchase Union Street Athletics from Sherry Haller, who has owned it for 21 years, and will merge the business with Young’s MMA. Haller will maintain ownership of the building and will be the landlord.

Young and Haller wouldn’t disclose the terms of the sale, but both said they are happy with the agreement.

“It will be Union Street Athletics: Home of Young’s MMA. That’s pretty cool,” said Haller, who is delighted about the prospects for the future of the business with Young at the helm.

“I’m really excited for the next chapter at USA and for our members,” said Haller. “It is bittersweet for me, but it’s time for someone else to take over and do real big things with it.

Young said he won’t tamper with the programs Haller established because they have provided a recipe for success for two decades while building a roster of almost 1,000 members.

“We’re going to fit our business inside USA and offer something what will make people happy,” said Young, who plans to keep membership rates “reasonable.”

“A huge part of what we do is group fitness programs and Young’s MMA offers a lot of fitness programs,” Haller said.

Haller said staff members from both businesses will be retained.

“Chris’s mentality is very similar to mine in that the members come first. Young’s is a very nice family and that’s what USA is all about so you’ll be meshing two families together into one huge family.”

Young admitted that fitting all the equipment from the two entities into one building “will be a little bit of a tight squeeze, but we’ll get it all in there.”

“Our goal will be to create this one-shop stop where you can go and get all the fitness you want,” said the 39-year-old Young. “Whether you want mixed martial arts, weight training, treadmills or (group) fitness programs, we will be able to provide all of that under one roof.”

USA will become the fourth home for Young’s MMA.

After his basement stint, it moved into Cushman Plaza on outer Hammond Street in Bangor and then to the old Bangor YMCA building, also on Hammond Street.

But the Bangor YMCA facility was condemned in April by the City of Bangor for a variety of violations and was purchased by Penobscot County the next day.

That temporarily left Young’s MMA without a home, but the business has spent the last several months at the former Great Skates building on Sylvan Road in Bangor.

Haller said the fitness industry has changed over the years and group fitness is important because it offers something low-cost, equipment-based fitness companies don’t.

“That component of working out together and supporting each other is something people really love. They like feeling like part of something bigger. They enjoy connecting with other people.”

Haller, who owns Hometown Pizza and Deli in Corinth, said she intends to pursue other business opportunities while also spending some time at USA: Home of Young’s MMA.

She joked that keeping a membership at “was part of the agreement.”