Though they seem quite different at first glance, Tetra Fitness’s 12 group classes have a few important traits in common. All of the classes, for example, follow the lead of an elite instructor with experience in personal training and biceps strong enough to arm-wrestle Atlas to a draw. All of them also adhere to the company’s core values, which include such rock-solid maxims as “be adventurous and creative” and “do more with less.” The indoor cycling class certainly embodies these two values with its 50-minute workout that sends riders racing over hills and steep inclines on straightforward stationary bikes. The aptly named Sweaty Weights class requires students of all skill levels to “be passionate and determined” as they strengthen and tone every single muscle in their bodies. When the instructors compel their students to “embrace change,” they can reference their own Barefoot Burn cardio class as an example. This intense workout focuses on flexibility, calorie burning, stretching, balance work, toning for all the connective tissues, core strengthening, and corrective exercises for the feet.