Gwyneth Paltrow, Kate Hudson, Gigi Hadid and Miranda Kerr have something in common: they all go to boutique fitness classes. From ModelFit to ShadowBox, specialized exercise classes are popping up on the East and West coasts like Starbucks. The latest is 'the class,' a 75-minute long workout that combines high octane cardio with sound to create a total cathartic experience (Christy Turlington and Naomi Watts are fans). Created by Taryn Toomey, a former executive for Dior and Ralph Lauren, the class mixes toning, aerobic, and anaerobic (essentially a focus on breathing) and lots of sound making—you’re encouraged to yell—to both exercise the body and let go of negative energy and bad habits. Consider it a mix of dance, yoga, and some traditional boot camp style cardio, but with an awesome soundtrack in one of the chicest studios around town.