Dyspnea

Under control conditions and every 30 s during RTs, subjects were asked to quantify the sensation of dyspnea, which was described to the patients as a nonspecific discomfort associated with the act of breathing. Patients quantified dyspnea by pointing to a score on a large Borg scale from 0 (none) to 10 (maximal). Specifically, the subjects were asked to quantify the intensity of the symptom by relating it to their common experience. The scale was a continuous vertical linear display associated with 10 verbal descriptors of the extent of the symptom, which corresponded to those of the 10-point Borg category scale. The subjects were instructed to indicate with a hand-controlled potentiometer how dyspneic they felt with reference to the category descriptors.  natural inhaler 
Protocol
All subjects were tested in the morning. Before the experiment, the subjects were well acquainted with the laboratory and equipment. An arterial blood sample and lung function tests were performed, and then changes in volume, flow, and Pes were recorded. Finally, the respiratory muscle strength tests were performed in each patient.