When you think about an exercise ball, you probably begin to imagine people sitting at desks, or using them for a modified sit up. You probably don’t imagine 6-pack abs and a strong core. Simple moves for your core can become serious fat blazers when you perform them with an exercise ball. A recent article in Muscle and Fitness demonstrated several exercises to perform with an exercise ball that challenge your muscles more than standard strength moves alone. The exercises are: Leg lifts Prone hamstring curl Stability ball dumbbell chest fly Seated dumbbell shoulder press with twist Mountain climbers Rear lunges with front raise One-leg suspended seated bicep curls Pushups with knee-ins .