Diaphragm adaptations elicited by severe chronic obstructive pulmonary disease: lessons for sports science.

In humans, the diaphragm adapts to severe chronic obstructive pulmonary disease with (a) fast-to-slow transformations of the fiber types and myofibrillar proteins and (b) increases in the activity of mitochondrial oxidative enzymes. We suggest that progressive endurance training over several decades accounts for these adaptations.