Low cost fitness chain The Gym Group has secured £50m of venture capital to expand its club portfolio - less than a month after rival Pure Gym announced it too would be spending £50m on new sites.

The Gym Group now has the backing of two private equity investors - Bridges Ventures and Phoenix Equity Partners. While it is the first time Phoenix has invested in the company, Bridges Ventures has supported the chain since its inception in 2007.

It is the latest sign that competition between the UK's low-cost gym operators is heating up.

Just weeks ago, in May, Pure Gym announced it would spend £50m on new sites following its takeover by US private equity firm CCMP Capital Advisors.

Pure Gym currently has 45 locations in the UK and has plans to add 40 new sites over the next 12 months, including 15 in London alone.

The Gym Group operates 36 sites and has announced plans to open 20 to 30 new gyms each year.

John Treharne, CEO of The Gym Group, said: "We welcome our new partner Phoenix alongside our existing partner, Bridges. This combination will allow us to fully capitalise on the opportunities in the rapidly growing low-cost gym sector.

"This investment will allow us to continue with the fast rollout programme and strengthen our focus on innovative technology to deliver a high quality, affordable offering."