Inclusion Criteria:  A plethysmography within subject's predicted values A negative metacholine test (no documented allergy) A hyperventilation provocation test result that is consistent with the Nijmegen questionnaire score, confirming either group classification (HVS+ or HVS-)  Exclusion Criteria:  Each of the following known or documented conditions: chronic bronchitis (COPD), emphysema, asthma, cardiac disorder, neurological disorder, gastrointestinal disorder, thyroid disorder or psychological/psychiatric disorder Suspicious cardio-pulmonary exercise testing (CPET) with cardiac or respiratory limitation Pregnant women or women in the process of becoming pregnant Persons with a diving practice (amateur or professional), High-level athletes, Active smokers and persons using morphine, and/or barbiturates, and/or anxiolytics and/or sleeping pills