Kettlebells are the brawniest of all the bells, unlike liberty bells, which crack under the pressure of democratic symbolism or a light northern breeze. Stay strong with today's Groupon: for $20, you get one month of unlimited classes at Big Sky Kettlebells (a $40 value).

Big Sky Kettlebells crafts lean muscles and bold bodies with its body-sculpting selection of kettlebell classes. Often associated with Russian lifters, kettlebell workouts carve the body's core with lifting and swinging motions, which mimic the muscle-grinding movements found in hard labor and extreme miming. Learn pound-melting tactics, tone extremities, and build muscle as you partake in a variety of endurance-enhancing exercises. Classes run Mondays and Wednesdays at 6 p.m. and Saturdays at 11 a.m. Your very first session with Big Sky Kettlebells is free, so try out your first kettlebell class and then redeem your Groupon for a month of unlimited body bettering.