A Christchurch mother is upset she was not allowed to take her newborn baby to the gym with her.

First-time mother Lucy Carey "nearly burst into tears" when she was told her 12-week-old son, Max Houghton, posed a health and safety risk at the QEII Fitness Centre in Parklands.

"I specifically joined the council gym because I wanted to support my local council after I moved here," she told Stuff.

"I feel discriminated. It's like I'm not allowed to work out. It's ridiculous."

Christchurch City Council recreation and sports manager John Filsell told Stuff it was not safe for her to have Max with her with the large number of free weights in the gym.

"It's a dangerous environment for very young children. One slip up and the consequences could be really dreadful."

Ms Carey says she cannot leave Max with a carer because he was born 10 weeks prematurely.

There are other council-owned pools and sports halls which have professional supervisors for young children, Mr Filsell says.

The AM Show hosts weighted in on the matter on Thursday morning.

"If you're going to do a weights session you're not going to put a 12-week-old baby down next to you," sports presenter Nicky Styris says.

"I agree there are health and safety risks," show host Duncan Garner says.