Constant work rate tests are viewed as the most suitable and sensitive method to assess exertional breathlessness. The 3-minute constant rate treadmill test (3-min CRTT) is a validated test wherein participants exercise at an intensity determined by an incremental test. For the purpose of this study, participants will perform three 3-min CRTT at 75% of peak power output, achieved during an incremental treadmill exercise test, under three experimental conditions: (i) fan to the face; (ii) fan to the leg; (iii) no fan. The order of the experimental conditions will be random for each participant. Cardiac and dynamic respiratory parameters will be collected breath-by-breath at rest and during exercise using the Hexokin Smart Shirt. In order to target the intranasal pathway located on the trigeminal nerve that is hypothesized to modulate the mechanisms governing the potential effectiveness of a fan to the face, a metabolic cart will be omitted due to the use of the facemask or mouthpiece and nasal clip that would block this pathway.~Using the Borg 0-10 scale, perceptions of breathlessness intensity, unpleasantness and leg fatigue will be assessed at rest, within the last 15-seconds of each minute of exercise, and at end exercise or the symptom limited peak of exercise. Two areas of facial skin temperature, one at the forehead to target the ophthalmic branch of the trigeminal nerve and the other at the cheek to target the maxillary branch of the trigeminal nerve, will be measured prior to exercise, within the last 15-seconds of each minute of exercise, at end exercise, and following exercise using a medical grade non-contact infrared forehead thermometer. The model number of the forehead thermometer that will be used is THERMOPROPCV2 and is licensed by Health Canada and approved by the U.S. Food and Drug Administration (FDA), CE approved with European health, safety, and environmental protection standards, and approved by the Restriction of Hazardous Substances Directive (RoHS).
A fan blowing cool air to the face has been shown to alleviate breathlessness in malignant and non-malignant disease at rest and during exercise, however the underlying physiological mechanisms remain unknown. This random order, three-condition design study will explore physiological mechanisms of breathlessness relief with fan-to-face therapy during constant-rate exercise in people with cardiorespiratory disease.