Heavy Metal CrossFit @ The Lab Gym, St. Louis

Justin Thacker, the muscle-bound founder of The Lab Gym, uses the same principles that motivated him through 20 years of weightlifting experience to spur on and cultivate a community of health-conscious exercisers at his modern, glass-walled gym. His team of expert trainers leads guests through group fitness classes that turn bodies into granite sculptures through a series of weightlifting routines and the crystallization of magma. Patrons can coax coy muscles from epidermal hideouts with free weights, dumbbells, squat racks, and an expansive cardio circuit, all accessible to members by keycard 24 hours a day.

For custom guidance, guests can pair up with a personal trainer or can sign up for the structured Laser weight-loss program, a regimen designed to blast off pounds with a laser focus but without actual lasers.