Pulmonary changes during exercise
During exercise, the body's demand for the oxygen needed in cellular respiration increases, and this requires the body to do some adjustments. The cardiac output and pulmonary blood flow increase, while the pulmonary vascular resistance decreases. The result is an increased space of the lung that is perfused, which decreases physiologic dead space and increases oxygen delivery to exercising tissues. Furthermore, due to an increase in acid production and temperature, the hemoglobin's affinity for oxygen decreases, which favors the delivery of oxygen to tissue in need.