Swinging a hula hoop around her hips has helped Mary-Beth Acres shed more than 30kg of weight.
The 22-year-old, who now holds adult and children's hula hoop classes, said she hadn't hula hooped since she was a child until about two years ago.
Her mum, Judith Acres, had taken up horse riding and her instructor advised her to use a hula hoop to "improve her jumping seat", but they weren't able to find an adult hula hoop anywhere, Miss Acres said.
"Using a hula hoop strengthens the core muscles in your pelvis."
She decided to make one for her mum and started hula hooping herself and soon noticed the weight dropping off, she said.
"The first 20kg came off really fast ... I couldn't believe it," she said. She was about 120kg two years ago and now is slightly less than 90kg.
Miss Acres said she hadn't set out to loose weight.
"It's like a full gym workout ... it's not like dance but a low-impact exercise." She only hula hoops for about 30 minutes daily.
Today she makes and sells hula hoops and runs classes for both adults and children.
Most people think they can't hula hoop, but Miss Acres said anyone could swing a hoop on their hips, they just needed the right-sized hoop. She has an 83-year-old who is hula hooping.
"It's not one size fits all. I was a skinny kid and I couldn't hula hoop. Some people, don't give it a go because they don't think they can do. It's a self image thing."
Miss Acres is training towards a sports fitness and development certificate.
If you are interested in buying a hula hoop or joining a class check out: www.facebook.com/SercasHoops or call 022 350 8344.