Any new mother will tell you that parenting is a workout, but a world-first baby sling designed in Australia takes the concept to a whole new level.

The Smiling Sling, invented by Sydney mum and personal trainer Nikolinka Krstanoska-Blazeska, features elasticised bands that transform a baby into a living, breathing gym weight.

Using the baby like a dumbbell, barbell or medicine ball, parents don the sling and do bicep curls, lateral raises and a host of other exercises.

Ms Krstanoska-Blazeska said babies loved the movement and parents enjoyed the bonding time.

“I have spent so much time with mums at the gym and I was always holding the bubbas,” she said. “I thought: there must be a way to do the exercise and hold the baby safely, and that’s how we came up with the design.”

Ms Krstanoska-Blazeska was recently granted a worldwide patent and is preparing to market the sling globally.