The Gym Group experienced a 21 per cent year-on-year increase in the number of member visits in during the first month of 2017, making it the firm’s busiest January ever.

Over the course of the month, 379,000 extra member visits were recorded across the chain’s 89 sites.

The growth, according to The Gym Group, is being driven by a surge in ‘millennial’ customers visiting the gyms, with a members’ average age of 32.

Student membership of The Gym Group grew by 23 per cent over the last 12 months, while 35 per cent of members in university cities such as Brighton and Nottingham were students.

The Gym Group offers membership from £12.99 per month with no contract, and chief executive John Treharne said the “flexibility” was a driver behind the growth in youth membership.

“It’s great more young people are joining The Gym and realising the benefits of regular exercise,” he said.

“We are really proud that our gyms help break down the barriers to exercise and we can welcome so many new gym users every month with more than a third of joiners never having been gym members before.”