Fig. 2.

Chamber study bubble scores as detected by TTSCE in subjects performing cycle ergometer exercise in normobaric normoxia (NN; A), hypobaric normoxia (HN; B), normobaric hypoxia (NH; C), and hypobaric hypoxia (HH; D). Normoxic workloads are 100, 130, and 160 W. Hypoxic workloads are 70, 100, and 130 W. Max, highest workload achieved within subject and corresponding bubble score. *P < 0.05 for NN compared with HN and NH compared with HH. Circles are normoxia, squares are hypoxia, open symbols are normobaric, filled symbols are hypobaric.