↵^a Resting breathing pattern and mechanics were measured with the infant in a calm, awake state every morning with a respiratory monitor (Philips-Respironics CO₂SMO). After inspiratory muscle strength training, infants used a slower, deeper breathing pattern with reduced airway resistance in preparation for ventilator weaning. The “Pre” measurements reflect the infants' status at rest, prior to the initial evaluation. The “Post” measurements were taken at rest, prior to the last session of inspiratory muscle strength training and extubation. IMV=intermittent mandatory ventilation; C_dyn=dynamic compliance, R_awi=dynamic inspiratory airway resistance; R_awe=dynamic expiratory airway resistance; PaO₂/FiO₂=partial pressure of oxygen, arterial/fraction of inspired oxygen, N/A=not applicable.