This review discusses the distribution of ventilation in the normal adult lung and includes the influence of quiet and deep breathing on regional ventilation. The effects of breathing at low lung volumes; inspiratory flow rate; posture; age; and body weight on ventilation are also described. A selection of breathing exercises are examined with regard to their ability to influence regional ventilation. There is no evidence that breathing control (diaphragmatic breathing exercises) improves regional ventilation to the dependent zones of the lungs. Limited evidence does suggest that thoracic expansion exercises, whereby respiratory muscles are voluntarily contracted to alter regional chest wall expansion, can improve underlying ventilation. However, there remains a paucity of evidence regarding the effects of breathing exercises on regional ventilation.