Lung capacity was the maximum volume of air an individual's lung(s) could hold at any given time. Having a greater lung capacity could be an advantage for some individuals, such as athletes and warriors. (VOY: "Lineage")
In 2371, The Doctor assured Kes that her lightheadedness following her donation of a lung to Neelix would soon pass as she adapted to her newly diminished lung capacity. (VOY: "Phage")
In 2377, The Doctor determined that Fantome had an unusually large lung capacity. (VOY: "The Void")