Dyspnea Evaluation: Dyspnea intensity (defined as "the sensation of laboured or difficult breathing") and perceived leg discomfort will be evaluated at rest, every minute during exercise, and at peak exercise using the modified 10-point Borg scale on all testing visits. Participants will be asked to describe their dyspnea during exercise after the intensity ratings at end-exercise using the following 3 descriptors: (1) "my breathing requires more work and effort" (work and effort); (2) "I cannot get enough air in" (unsatisfied inspiration); (3) "I cannot get enough air out" (unsatisfied expiration). None to all 3 of the descriptors can be chosen at any one time. Upon exercise cessation, participants will be asked to verbalize their main reason(s) for stopping exercise (i.e., breathing discomfort, leg discomfort, combination of breathing and legs, or some other reason) and to select qualitative descriptors of breathlessness using an established questionnaire.