The South African private equity firm Brait acquired an 80% stake in this health club operator in 2015 from CVC Capital Partners, with Sir Richard Branson’s Virgin Group cutting its stake to 20%. The deal valued Virgin Active at £1.3bn. The group decided to focus on its London business at the start of 2016, and since then has sold 51 of its UK gyms to the likes of David Lloyd Leisure (No 52 on this year’s list). It has more than 1.4m members across 245 clubs in 10 countries, and is investing £150m in opening up to 40 new clubs in southeast Asia. In February, it reappointed founder Matthew Bucknall, 57, as group chief executive.