A primary objective of mechanical ventilation is to alleviate the intolerable effort of breathing while allowing the patient to perform enough work to prevent atrophy. By assuming the workload associated with breathing, mechanical support averts ventilatory failure, prevents respiratory arrest, assures CO2 removal and pH homeostasis, while permitting the overtaxed respiratory muscles to replenish energy reserves as the primary process is addressed. Skillful manipulation of the breathing workload can often facilitate the ventilator withdrawal process. The objectives of this article are to characterize the magnitude of ventilatory work performed by the machine and patient during mechanical ventilation and to formulate a strategy for minimizing the breathing workload.