More than a million members will be able to cancel their contracts early should their circumstances change in a way that makes attendance at the gym difficult or unaffordable, for example if they lose their job or suffer an injury

The gyms have also committed to greater transparency about key membership features, including initial membership periods and cancellation rights, and for these to be provided upfront as part of the sales process.

This follows agreement earlier this year by Bannatyne Fitness Limited, David Lloyd Leisure Limited and Fitness First Clubs Limited to change their contract terms.

Cavendish Elithorn, OFT executive director, said: “As a result of our investigation, millions of gym members now have better contract terms, including improved cancellation rights that prevent them being unfairly locked in if their circumstances change. This should be a warning to the rest of the industry that we will not hesitate to take action where we find evidence of consumers being treated unfairly.

“Anyone considering joining a gym or health club should carefully consider the contract terms before signing up. Consumers should shop around and ask questions. Alarm bells should ring if gyms are not being clear and upfront about their terms and conditions, including the length of the contract and cancellation rights. If consumers are told something that is not in the terms and conditions, they should ask for written confirmation.”

The OFT is also today writing to 20 other health and fitness operators, highlighting contract terms and commercial practices which may be considered unfair and advising them to review their contract terms.