The high-intensity 45-minute workouts change regularly.
"We have programs where you turn up one day for the quarterback session and train like an American quarterback then the next day is pipeline where you train like a surfer,"he says.
Cross Fit boxes are F45's biggest competitor but Deutsch says his business has broader appeal.
"We strip out the heavy weights and we don't do any power lifting,"he says."It is far less intimidating for females. Sixty-five per cent of our clients are female."
Let's franchise this
McDonald's,Subway,Dunkin' Donuts didn't even go close to that.
Rob Deutsch
Things took off when Deutsch brought Adam Gilchrist (not the cricketer) on board as a business partner.
"He's a franchise expert and he saw what I was doing and said'let's franchise this'and we did and it's been a pretty amazing ride,"Deutsch says.
F45 franchises are sold for $50,000 each. Franchisees then have to purchase around $100,000 of equipment and pay a $1500 a month fee.
Set up costs are low compared to traditional gyms due to the limited amount of equipment used at F45.
"Theres not a huge amount of equipment involved and it keeps us versatile,"Deutsch says."We definitely don't have those big cumbersome old school treadmills,elliptical machines or squat racks. Anything that can't be moved to the side we don't use."
F45 attendees pay $65 a week and can train as often as they want.
"Turnover is around $400,000 per annum for each unit,"Deutsch says."They are good little businesses. There's not many businesses where you can get that turnover."
Taking on the world
Initially Deutsch didn't spend any money on marketing F45.
"We got a little bit of traction on social media,"he says."The first five to ten studios were all sold through social media. The two most powerful marketing tools for us are social media and word of mouth."
It didn't take long until Deutsch was fielding enquiries from overseas.
"A lot of people have visited Australia and visited an F45 studio or[Australians] train at F45 and call their[overseas] friends,"he says.
He's relocated to Los Angeles to focus on the United States market where F45 is opening 25 franchises a month.
"In the UK we have sold 20 franchises in the last two months,"Deutsch says."That has been really aggressive. We're about to open in the Netherlands,France,Germany and Ireland. Europe is looking really buoyant."
He plans to open 1200 F45 studios worldwide by the end of the year tapping into growing interest in health and fitness.
In Australia alone IBISWorld predicts revenue in the gym industry will grow at a compound annual rate of 9.3 per cent over the five years through 2016-17,to reach $2.1 billion.
Bruce Billson,head of the Franchise Council of Australia,backs growth in the sector.
"In the health and wellness space there is abundant positive momentum with people focusing on their personal health and seeing franchised businesses being able to support that ambition in an accessible way,"he says.
A big kick
Deutsch says F45 won't fly under the radar for much longer.
"In Australia a lot of the studios we have sold haven't opened yet,"he explains."Only 260[of the 480] have opened. Over the next year we are going to go through a big kick."
He hasn't looked back to his days as a banker.
"I was 11 years working in finance and I hated every single day of it and now I'm the happiest man alive,"Deutsch says."If you have an idea and concept you think is going to work then definitely get out there and have a crack."
An earlier version of this article incorrectly listed the cost of attending F45 as $55 a week and the franchise fee as $500,000.