Table 1.

Quadriceps and diaphragm structure and function in patients with COPD compared with controls

	Quadriceps	Diaphragm
Strength	Reduced	Unchanged
Endurance	Reduced	Increased
Overall CSA	Reduced	Unchanged
Single-fiber CSA	Reduced in type IIX	Reduced in type I
Fiber type shift	Type I to II	Type II to I
Capillary and mitochondrial density	Reduced	Increased
Metabolism – oxidative: glycolytic ratio	Reduced	Increased

Abbreviation: CSA, cross-sectional area.