John Treharne, founder of The Gym Group, has been appointed chair of boutique fitness brand Frame.

Frame was launched by entrepreneurs Pip Black and Joan Murphy in 2009 with a central ethos that keeping fit and healthy should be "fun, positive and never a chore".

Offering 30 different exercise classes – across fitness, dance, barre, yoga and Pilates – Frame's pay-as-you-go model prices each class at around £10.

The company secured the backing of investor Piper in 2017 and currently has six London studios.

Frame is preparing to open a seventh studio in Angel, with its first two studios outside London, in Brighton and Bristol, planned for 2020.

"I’m delighted to be joining Pip, Joan and their talented team at Frame," Treharne said.

"They have done a tremendous job in building their brand and gaining such a devoted following among their customers. There is so much potential to develop this unique business further and I’m excited to be helping them along the journey."

Co-founder Pip Black added: "We’re so excited to have John, a fellow disruptor, as our chairman. He shares our passion for making it as easy and fun as possible for people to get and keep active.

"His guidance will be immensely valuable as we continue to grow Frame, while retaining all the elements that make us stand out in this marketplace and create a world-class experience for our Framers. We are really looking forward to working with him."

Treharne launched his first gym business, Dragons Health Clubs, in 1991, taking it public before it was sold in 2000.

He then launched The Gym Group in 2008, introducing the low-cost gym model with contract-less, 24-7 operations and online sign-up.

The Gym Group listed in 2015 and has more than 170 sites nationwide. Treharne stepped down as CEO in 2018, but remains on the board as founder-director.