Bad Boy Gym, Berkley

At Bad Boy Gym, amateur athletes train toward fitness prowess through kickboxing, in a no-frills, full-boxing-ring environment. The gym’s powerhouse instructors shepherd students through group sessions to blast fat from bodies as they train under the royal-blue ceiling. Insanity classes put students to the test with intense intervals of cardio kickboxing to forge a full-body, and cardio-conditioning workout. Eschewing group classes for the plentiful bonus balls and resistance bands, guests can forge fitness paths on their own. They can improve their musculature by shadowboxing in the ring, whip endurance levels into shape with jump ropes, or pummel a punching bag until it promises to train them personally.