Tracy Anderson
Celebrity insiders have worshiped fitness trainer Tracy Anderson for years, but it wasn't until she struck up a relationship with Gwyneth Paltrow that she basically became a household name. After Gwyneth gave birth to son Moses in 2006, she begged Tracy to come work with her full-time, and it was the beginning of a very fit friendship. Gwyneth even cut ties with Madonna after the singer dropped Tracy as her trainer. #Loyalty.