Although feeling the burn during a workout is generally a good sign, feeling the burn while sitting on the sofa is generally a sign your sofa is in the fireplace. Engage in controlled, constructive body burning with today's Groupon: for $20, you get 12 boot-camp classes at Next Generation Fitness 24/7 in Madison (a $180 value).

The attentive trainers at Next Generation Fitness 24/7 fortify muscles and willpower during motivating boot camps for adults and children. Each camp incorporates strength-building bodyweight exercises and endurance-boosting cardiovascular drills, which may include cycling and running from fast-food mascots. Gym-class classics, such as jumping jacks, join stationary-bike rides and jogging intervals to burn calories and raise energy levels, and Next Generation also invites fitness-seekers to sample a free P90X class, which cross-trains the body into top form with dumbbells, resistance bands, and pull-up bars. Adults can attend one class each day, Monday–Thursday at 5 a.m. or 6 p.m., though parents of pint-size exercisers should call the gym for a kids' boot-camp schedule.