We can keep this simple. Anyone who has a butt and can hold a barre should be able to join this class. It’s a constant burn, whether at the legs, core, arms, or glutes. “It’s a muscle endurance workout where you are challenged to stay in the exercises as long as possible in order to fatigue and sculpt the muscles, First-time barre goers often experience their muscles shaking or vibrating, which may be a new experience. This is a good thing. It means your deepest core muscles are fatiguing. So don’t let the shaking discourage you.