It’s a misconception that doing weights bulks you up, it in fact also helps you slim down and revs up your metabolism permanently. So head to the weight room, and when you feel like quitting, ask yourself why you started. The secret to shedding pounds is actually to build muscles. Go on, workout with weights. Another option is circuit training, which involves moving quickly from one exercise to the next, and burns 30% more calories than a typical weight workout. It blasts fat and sculpts muscle, burning up to 10 calories a minute.