Around 750,000 gym users have saved £37m (US$48.1m, €42.9m) as a consequence of interventions by the Office of Fair Trading (OFT).

Investigations by the arms-length body have led to almost 30 gyms reviewing their terms and conditions, thus benefitting several members.

In 2011, the OFT urged all gyms to check their contract terms were “fair and lawful” after the High Court ordered Ashbourne Management Services Limited not to use “unfair terms” following complaints by customers that they had signed long contracts they could not cancel.

Two years later, six other gym operators agreed to give members better cancellation rights and make their contracts “easier to understand”. A further 20 were asked to review their terms subsequently.

The OFT’s interventions have been followed by a number of chains launching pay-as-you-go packages.

The Competition and Markets Authority (CMA) has since taken on some of the OFTs’ consumer enforcement powers, and evaluated its work.

“Our evaluation has shown that the approach taken by the OFT has secured lasting change in the sector, brought benefits to consumers and can be applied to future work by the CMA,” said CMA senior director John Kirkpatrick.

“These consumer benefits were worth around £37m over three years in the gyms investigated by the OFT alone, and we think there are wider benefits to gym users across the sector.”