Like a good horror movie, a good exercise regimen shocks the body out of its lethargy, which is why so many personal trainers chase their clients on treadmills while brandishing anacondas. Get in less terrified shape with today’s Groupon: for $39, you get 10 CrossFit training classes at CrossFit Purgatory (a $150 value).

CrossFit Purgatory assaults unfitness in a no-frills, high-intensity gym environment that emphasizes community and functional, productive exercise. Led by owners Tony and Marcy Brown, CrossFit Purgatory’s coaches teach learnable techniques drawn from Olympic lifting, gymnastics, Strong Man training, and other schools of aggressive health, putting participants' bodies through ever-fresh paces while keeping them safe from the wires and pulleys of training machines. Each one-hour class leads with a warm-up with skill-specific exercises from the sport of the day, followed by an intensive workout and a cooldown, all fueled by simple objects, such as ropes and medicine balls, to whip muscles into shape. The workout of the day is customizable with variable repetitions and weights so that heavy lifters take on different challenges than long-distance runners, whose workouts are distinct from mountain-climbing sumo wrestlers. All participants may improve their capacity for work and strain under the coaches’ expert tutelage and the heft of dumbbells and classical human pyramids. In addition to the grownup exercise zone, CrossFit Purgatory provides an area where children may play while their parents work out.