Trainer Chelsea Rupp warns all her potential students that CrossFit might become an addiction. When she first started training three years ago, she was astounded and enthralled by its challenging and effective workouts, and was instantly hooked. After receiving her Level 1 CrossFit certification, Chelsea founded her own CrossFit gym—CrossFit GSL—where she and a team of enthusiastic trainers lead students of all levels in the high-intensity, ever-changing routines. Surrounded by the colorful flags and bright walls of their studio, the trainers guide students through warm-ups and functional workouts, scaling the drills' intensity to accommodate varying fitness levels. They encourage each student to push past their previously set boundaries as they heave barbells and kettlebells, jump rope, hop on large wood blocks, and toss medicine balls. The supportive instructors dole out nutritional guidance as well as postworkout recovery tips, such as techniques for therapeutic stretches and tips for mending shirts torn apart by bulging muscles.