The lungs

Expansion of / decrease in the number of alveoli (and therefore of the total respiratory surface)
Reduction of the elasticity of the lungs due to a higher proportion of insoluble collagen
Thickening of the basal membrane in the lung capillaries
The functioning of the lung depends on the mobility of the thorax
Age-related rib cartilage ossifications of the spinal column lead to increased shrinkage of the thorax
Reduction of the vital capacity and maximum ventilation (see fig. 2) (c.f. Weineck, Sportbiologie (Sport Biology), 2000)