Fig. 2.
Minute ventilation (V̇e), tidal volume (VT), and breathing frequency (fb) in nonasthmatic (A, C, and E) and asthmatic subjects (B, D, and F) during spontaneous (SVT) and maintained (MVT) ventilation trials. During SVT, V̇e, VT, and fb fluctuated with the changing exercise workload in both subject groups. During MVT, VT and fb, and thus V̇e, were maintained constant during the final 3 low-intensity workloads (i.e., Low-2, Low-3, Low-4). There were no differences between nonasthmatic and asthmatic subjects. *P < 0.05 vs. SVT trial.