Pink's trainers ''kicked her butt'' to lose her baby weight.

The 'So What' hitmaker gave birth to her daughter Willow Sage in June 2011 but after struggling to shift the extra pounds she enlisted the help of personal trainers Jillian Michaels and founder of the Hollywood Trainer fitness Jeanette Jenkins to ''inspire'' her to get back into shape.

She said: ''They both kicked my butt more than any other person I've ever worked out with. They're both amazing, and their bodies were all the inspiration I needed to get back into shape.''

Pink - real name Alecia Beth Moore - put on 55 pounds during her pregnancy and she blames the huge quantities of cheesecake and ''sour'' candy and deserts she ate for her weight gain.

The 33-year-old singer is absolutely ''smitten'' with Willow and the little girl has made her and her husband Carey Hart happier than they could have ever imagined.

In November's edition of SHAPE magazine - in which she graces the front cover showing off her toned abs - she said: ''I'm so in love with her. I'm totally smitten! It's just pure joy for Carey and me. Willow has made us more fun - we're this cool little threesome.''

The pop star is loving motherhood so much she revealed last month she would love more kids and if she wasn't so busy preparing for her 2013 tour to promote new album 'The Truth About Love' she'd get pregnant.

She said: ''I mean if I weren't going, getting ready to go on tour, I'd be pregnant. I'm barefoot and pregnant in my garden with an attitude!''