A University of Canterbury communications spokesperson, who did not want to be named, said there was no dress code at the recreation centre. Instead, it had a code of conduct that all members received when they signed up for the gym.
The centre's user guide pamphlet urges gym users to be mindful of others, and that they must wear "tops that cover the midriff, and shorts that provide full coverage of buttocks for the duration of your workout".
A recreation centre receptionist said the guideline was in place to reduce skin contact with machines, and to meet hygiene standards.
University of Canterbury student, Brittany De Stadler, was shocked to hear about the rules.
She said the rules were new to her. The recreation centre had not informed her of the code of conduct.
"They never ever told me about or directed me to a code of conduct. I honestly didn't even know they had a code of conduct," she said.
Commercial gyms such as Snap Fitness and Anytime Fitness do not impose clothing retstriction on women.
Snap Fitness CBD manager Chris Thrasher was surprised by the university gym's rule and questioned whether it was in place to reduce skin contact with machines.
"Your hands are touching them [machines] all the time anyway... so I'm not too sure where that one's coming from to be honest. Your hands perspire a lot more than your stomach would."
Anytime Fitness Cashmere club manager Craig Maguire agreed with Thrasher. He believed women should be able to choose what they wear.
"I don't see it as an issue. As long as people are comfortable then that's their issue."
The only clothing requirement all three Christchurch gyms share, is that gym-goers must be wearing appropriate shoes.