Smith and partner Teagan Voykovich have revealed they have joined forces to set up an F45 Training studio franchise.
Part of an international training craze, the studio (gym) is located in a light industrial and residential part of South Dunedin.
Other top sportspeople have got behind F45 too.
Kiwi cricketer Mitchell McClenaghan - who is hoping for a Black Caps recall in the coming cricket season - became an ambassador for the brand last year and has opened a studio in Auckland's Howick.
F45 Training began in Australia and the head office says more than 900 franchises have been sold in more than 30 countries.
The new South Dunedin gym owners didn't want to be interviewed, but Voykovich responded by email to a Herald on Sunday inquiry.
"We are currently in the fit out stage, would love to talk closer to our grand opening," she said.
Smith was disciplined by New Zealand Rugby after an incident at Christchurch Airport in 2016, when he was busted in a public toilet with a woman.
He later made a wide-ranging apology.
"I've made a huge mistake, a huge error in judgment. I'd firstly like to say a huge sorry to my partner Teagan, her family, my family," Smith said.
F45 combines elements of high-intensity interval training, circuit training, and functional training.
It pairs interval cardio and strength training, which the F45 organisation says has been shown to be the most effective method of burning fat and building lean muscle.
It involves 27 different 45-minute workouts and there's a meal plan too.
Dozens of F45 studios have been opened or are about to be opened around New Zealand and the craze is claimed to be the world's fastest-growing training phenomenon.
The F45 system was devised by the Sydney celebrity trainer to film stars Leonardo di Caprio, Nicole Kidman and Hugh Jackman.
Smith is set to be named on Monday as a member of the All Blacks squad to compete in the Rugby Championship that kicks off with a test against Australia in Sydney on August 18.
He is considered one of the best No 9s to wear the All Blacks jersey.
