Rumble Boxing | 11,194 followers on LinkedIn. Boxing ✖️ Strength Training 🥊 💥 Explosive, full-body group fitness classes for all levels | BOXING-INSPIRED GROUP FITNESS CLASSES 10 rounds 2 styles of training. 0 experience necessary. Rumble Boxing pairs the skills & drills of boxing with strength training -- It's HIIT (High Intensity Interval Training), strength training, metabolic conditioning (METCON), and explosive cardio circuits in one seamless class.