Ventilatory Responses to Hypercapnic and Hypoxic Conditions in Hyperventilants

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