Monthly fees at Hong Kong’s 24-hour fitness centres vary widely and can more than double depending on additional charges, the Consumer Council has found, as it warned residents to be cautious when providing sensitive personal data, including facial images for recognition systems.

The consumer watchdog revealed on Monday the results of a survey of 11 round-the-clock gym operators, finding that although all offered monthly membership plans, nearly half imposed extra non-refundable charges that significantly increased costs for short-term users.

“Consumers should first understand whether the centre would charge other fees on top of the monthly fee and consider their own workout habits before making a purchase decision,” said Kenneth Chan Kin-nin, vice-chairman of the council’s Committee on Sustainability, Public Affairs and Education.

The council collected information on service fees and membership terms between November and December last year, using both website research and direct verification with operators. It also sent staff as mystery shoppers to 22 gym branches across the city to observe facilities and test membership sign-ups.

While all centres provided monthly membership options, five required payments beyond the basic monthly fee, including enrolment charges or fees for electronic keys or key cards. Four centres also demanded deposits.

When these additional costs were distributed across short membership periods, the price difference became significant, Chan said.