The new mother has swapped her gold jewellery and stilettos for sweatbands and trainers in preparation for a triathlon in Malibu next month in order to get her famous curves back in shape – and she’s on a mission to tell fellow new mums to do the same.

“You’ve got to start slow and give yourself time,” preaches Jen, 39. “This is not something that is natural to me but it’s something that is a challenge and I’m always into challenging myself and seeing what I can do. You have to start little by little and you just work up to it.”

But the pop diva, who gave birth to twins Emme and Max earlier this year, isn’t enjoying every aspect of the three-sport event: “The swimming is a killer, I’m not going to lie.”