Mild intermittent hypoxia (IH) initiates sustained increases in chest wall and upper airway muscle activity in humans. This sustained increase is a form of respiratory plasticity known as long-term facilitation (LTF). Repeated daily exposure to mild IH that leads to the initiation of LTF of upper airway muscle activity could lead to increased stability of the upper airway. In line with PI's laboratory's mandate to develop innovative therapies to treat sleep apnea, this increased stability could ultimately reduce the continuous positive airway pressure (CPAP) required to treat obstructive sleep apnea (OSA) and improve compliance with this gold standard treatment. Improved compliance could ultimately serve to mitigate those comorbidities linked to sleep apnea. Moreover, in addition to improving CPAP compliance numerous studies indicate that mild IH has many direct beneficial effects on cardiovascular, neurocognitive and metabolic function. Thus, mild IH could serve as a multipronged therapeutic approach to treat sleep apnea. In accordance with this postulation, our proposal will determine if repeated daily exposure to mild IH serves as an adjunct therapy coupled with CPAP to mitigate associated co-morbidities via its direct effects on a variety of cardiovascular, metabolic and neurocognitive measures and indirectly by improving CPAP compliance. Modifications in autonomic (i.e. sympathetic nervous system activity) and cardiovascular (i.e. blood pressure) function will be the primary outcome measures coupled to secondary measures of metabolic and neurocognitive outcomes.