Barry's London East

With their focus on high calory burning and the ominously sounding “Red Room” exercise space, the Barry's gyms aren't for the faint of heart. The bootcamp classes at this global group are designed as challenging workouts where you'll burn upwards of 1000 calories per hour and achieve fitness levels you didn't think were possible. After the gruelling workout, head to their Fuel Bar to rehydrate, recharge and recover. The London East branch also features a deck with lounge chairs.