The bad blood boiling between Madonna and Tracy Anderson since their 2009 split has everything to do with Madge's current trainer, Nicole Winhoffer, says a source. We're told Anderson trained Winhoffer for a year and introduced her to the pop legend. "Nicole was overweight until Tracy shaped her body," snarks the insider. "She was a caterer, and wanted to be famous. Tracy had been living with Madonna in London but moved back to the States to spend time with her family, and sent Nicole in her place." The source said Nicole was working for Tracy and learned all her moves. Adding, "Nicole doesn't understand the reasons behind the moves, just the motions." At the time of the split, Page Six was told, "Madonna had grown tired of the baggage that Tracy always seemed to be carrying with her," that it had become a "distraction," adding further problems arose when Anderson developed a relationship with Philippe van den Bossche, the former head of Madonna's Raising Malawi charity who was forced out for alleged mismanagement.