Figure 1.

Potential factors responsible for the adaptation of skeletal muscle fiber type in response to chronic exposure to high altitude and under conditions of pathological hypoxia. COPD, chronic obstructive pulmonary disease; CHF, chronic heart failure; OSAS, obstructive sleep apnea syndrome; ERR- α, estrogen related receptor-alpha. Vertical arrow, activation; Vertical blunt arrow, inhibition; ↘, decrease.

: Factor most likely responsible.

: Factor possibly responsible.

: Factor most unlikely responsible.

: Role played unclear or unknown.