Madonna's former trainer claims the star was too "demanding".
Tracy Anderson, who worked with the 'Like A Virgin' hitmaker between 2006 and 2009, famously fell out with the singer and Tracy has now revealed that the pair parted company after Tracy missed one of her kids' concerts because Madonna had a training session.
Tracy told The Times newspaper: "Madonna can demand whatever she wants to demand, she's Madonna, that's just what it is. It wasn't working for me because my demands are, like, I have a kid. When I missed my son's saxophone concert because of a training session with her, I was like, 'I can't do this anymore.' That was it for me."
Madonna had previously gushed about working with Tracy, who also cites Gwyneth Paltrow as a fan and now a business partner.
Speaking in 2009, Madonna said: "Tracy Anderson is my saviour. After two Caesareans, three hernia operations and one riding accident that left me with 10 broken bones, she was the only one who could pull my body back together into one piece."
When they worked together, they used to train together six days a week.
Speaking of her fitness programme, she added: "We train for two hours six days a week. We do 45 minutes of dance aerobics, followed by work on muscle tone, flexibility and definition.
'"here's no running and no weights bigger than three pounds, because Madonna doesn't want to bulk up. Madonna's body is perfect. She has no fat, no cellulite, she is so toned, and her arms are amazing."
Tracy and Gwyneth teamed up to release a string of exercise DVDs - four in total - as well as a book, Tracy Anderson's 30-Day Method.
Writing about working with Tracy, Gwyneth previously shared: "Still, when I first started working with Tracy, finding motivation was hard. She advised me to think of exercise as an automatic routine, no different from brushing your teeth, to avoid getting distracted. Now it is part of my life."