Pairing up exercises that work opposite muscle groups (so they don’t compete with one another for recovery) burns more calories than traditional training with straight sets. For example, doing multiple sets of a chest exercise paired with sets of a back exercise shuttles blood back and forth between the working muscles, making your heart work harder. Increased heart rate means more calories burned, and training multiple areas of the body at once also leads to shorter, more intense, and more efficient workouts.
Science backs it up, too. A 2010 study in the Journal of Strength and Conditioning Research found that noncompeting supersets led to greater energy expenditure relative to training time and subjects burned calories at an accelerated rate.