Greek Australian fitness queen Kayla Itsines and former fiancée Tobi Pearce have sold their global health and fitness empire Sweat for the staggering amount of $400 million.

The dynamic duo sold their powerhouse platform to US software giant iFIT Health & Fitness Inc. six years after launching the first version of the Sweat app in 2015.

The young rich listers, who split early last year and are parents to daughter Arna, will continue to lead Sweat from Adelaide, where the business will be headquartered as a stand-alone brand within the iFIT group.

Mr Pearce wrote on Instagram that it was a proud day for the pair, who remained committed to building the business further from their home city.

“Kayla and I have had a very strong and long working relationship and this is the beginning of chapter two for both of us. Our headquarters will remain in Adelaide, and we have a second office in Melbourne and that will remain there as well,” he said.

The deal with iFIT follows months of speculation that Pearce, 28, and Itsines, 30, were seeking to sell the business they created together.

The pair, both personal trainers when they joined forces, shot to fame after forming the Bikini Body Guide fitness program in 2015 and were the youngest people to be featured in the Australian’s Richest list published in 2019 with an estimated combined worth of $487 million.

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Ms Itsines was also named the wealthiest female in the prestigious ‘2018 Financial Review Young Rich List’ aged 40 and under.

In the year to June 2020, their company generated $99.5, 11.2 per cent higher than 2019 as new subscribers signed up during the depths of the COVID-19 pandemic.

The US remains the company’s biggest market, where $53.7m of its revenue was sourced during the 2020 financial year, while Australian subscribers generated $8.7m.

Mr Pearce and Ms Itsines shared a $23.2m dividend in 2020 despite the company slipping to a $5.4m loss.

Mr Pearce said the tie-up with iFIT would enable further investment in the Sweat brand and would help accelerate its global expansion.

Despite their split, the pair have continued as business partners, with Pearce as chief executive and Itsines as head trainer and the face of the platform.

They were valued at $209m each on last year’s Young Rich List.

READ MORE: Fitness queen Kayla Itsines named wealthiest self-made female under 40 in Australia

Sweat has built a global fitness community of more than 50 million women across its social channels.

Ms Itsines said the deal with iFIT “opened the door to an exciting new future” for the brand.

“Sweat has had an incredible journey from our humble beginnings training women one-on-one in my Adelaide backyard to launching the Sweat app in 2015 to now joining the iFIT family,” she said.

“Sweat was founded on our simple belief that fitness can genuinely help women improve their confidence, health and quality of life. Through iFIT’s strategic leadership, we will be able to create new world class fitness content and product experiences to support more women on their fitness path forward.”

Utah-based iFIT is one of the world’s biggest health and fitness technology companies, with millions of members across 120 countries.

The company has an office in Melbourne and owns equipment brands including NordicTrack, ProForm and FreeMotion. It is valued at more than $US7bn in its most recent round of funding in late 2020 and is expected to attain a valuation in excess of that in an expected IPO later this year.

“Kayla, Tobi and the team at Sweat have built an incredible brand and community of fitness enthusiasts,” said iFIT’s Chief executive Scott Watterson.

“We are delighted to welcome Kayla’s authentic fitness training and charismatic personality – along with all of Sweat’s other star trainers – to the iFIT family.”