F45 offers 45 minute classes based on functional high intensity interval and circuit training and its investors include actorMark Wahlberg who took a minority stake in the business last year alongside FOD Capital.
Mr Deutsch started F45 in 2013 with personal trainer Luke Istomin and the pair then brought in franchise expert Adam Gilchrist (not the cricketer) to drive its expansion.
However Mr Istomin left the business in 2016 after what he said were"creative differences"and company searches show Mr Deutsch ceased his role as a director on 9 March this year just before the coronavirus pandemic battered the business.
Mr Gilchrist and F45's chief financial officer Christopher Payne are the fitness chain's two sole remaining directors.
Mr Deutsch recently posted on Instagram that he had transitioned out of his role as chief executive but remained a shareholder.
"As the founder of F45,I’ve had the privilege of helping build the company into one of the fastest-growing fitness franchises in the world,"he said."My time at F45 has been deeply rewarding and enjoyable. I am incredibly thankful for the business partnerships and friends made along the way."
Mr Deutsch said he was working on a new venture and he has recently been listed as a director of the businesses R2 Capital and Youngr.