Diameter changes of the rib cage and abdomen were recorded during tidal breathing and speech production in 12 adult male subjects grouped on the basis of prominence on three body type components: relative fatness, relative musculoskeletal development, and relative linearity. Data were charted to solve for lung volume, volume displacements of the rib cage and abdomen, and muscular mechanism. Tidal breathing differed across subject groups with regard to depth, rate, and chest wall configuration. Subjects rated high in relative fatness breathed deeper, slower, and with a greater chest wall deformation from relaxation than did other subjects: Speech breathing differed across subject groups with regard to relative volume contributions of the rib cage and abdomen, abdomeren excursions, rib cage paradoxing, and chest wall configuration. Subjects rated high in relative fatness demonstrated substantial abdomen contributions to lung volume change, large abdomen excursions, frequent rib cage paradoxing, and marked chest wall deformations from relaxation. By contrast, subjects rated high in relative linearity demonstrated large rib cage contributions to lung volume change; small abdomen excursions, and slight chest wall deformations from relaxation. Subjects rated high in relative musculoskeletal development generally represented a mixture of characteristics of the other two subject groups in their speech breathing performance. Functional differences are discussed in relation to possible underlying mechanism and inferences are drawn concerning evaluation and management of individuals with speech breathing disorders.