New mother Lucy Carey was shocked to find her baby wasn't welcome in a Christchurch City Council-operated gym.

A Christchurch mother "almost burst into tears" when she was told she could not to return to her gym with her newborn son as he posed a health and safety risk.

First-time mother Lucy Carey fed, cleaned and made sure her 12-week-old son, Max Houghton, was asleep before taking him into the QEII Fitness Centre in Parklands last Thursday.

She was excited about finally getting back into training and planned to join an athletics club in Christchurch next season.

"I didn't even make it to the front desk," she said.

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"They said to me if they let me bring my baby in, it would encourage other people to bring their babies in. I almost burst into tears."

JOHN KIRK-ANDERSON/STUFF Lucy Carey was denied entry to the QEII Fitness Centre with her 12-week-old son, Max Houghton.

Carey said the Christchurch City Council, which operated the fitness centre, should encourage people to keep working out after having a child, rather than discourage them.

"My whole life is about living a healthy, active lifestyle and I want to set my son up with that attitude right from the get go."

Her partner, Tom Houghton, is a physical education specialist and Carey is a public health dietician, meaning exercising and living a healthy lifestyle is a huge part of their lives.

JOHN KIRK-ANDERSON/STUFF The Christchurch City Council says the QEII Fitness Centre is not a safe place for babies.

The couple moved to Christchurch two years ago from Hamilton. Carey said the QEII Fitness Centre was a large reason why they moved to Parklands.

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

Carey said she was unable to leave her son with anyone else because he was born 10 weeks prematurely and had to be breast fed on demand.

"We're a healthy active family and part of that is taking him with me and breast feeding him … I can't be separated from him for a long period of time incase he wakes up hungry."

Carey said she wanted to show her son having kids would not stop her from keeping fit.

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

Before becoming pregnant, Carey competed in 100 and 200-metre sprint events.

She planned to look for another gym that would let her take her son with her.

"I don't want to stop what's become a real passion of mine (sprinting) and I really want to show my son that mothers and parents can do anything."

Christchurch City Council recreation and sports manager John Filsell said the large number of free weights at the QEII Fitness facility posed a large threat for young children.

If even the lightest free weight fell onto a baby in a pram, it would kill them, he said.

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

Filsell said the council's head of fitness would be speak with Carey about alternative options.

"We really sympathise and we absolutely try our best."

He said there were several council pools and sports halls where young parents could take their children and have them supervised by professional carers nearby.

"It's bloody courageous wanting to stay active so soon after having a baby; it's a brave step and we want to support that."