A Single Bout of Intermittent Hypoxia Increases Cerebral Blood Flow and Supports an Executive Function Benefit

Alternating between brief normoxic and hypoxic intervals (i.e., intermittent hypoxia: IH) increases cerebrovascular dilation, cerebral blood flow (CBF), and O 2 extraction. Some work has shown that the physiological adaptations arising from multiple IH sessions improve brain health and executive function (EF)—a finding linked to a post‐intervention improvement in cortical hemodynamics. Here, we provide a first demonstration of whether the physiological changes associated with a single IH session provide a transient post‐intervention EF benefit. Healthy young adults ( N = 24) completed an IH protocol entailing 12 alternating 5‐min normoxic (P ET O 2 = 100 mmHg) and hypoxic (P ET O 2 = 50 mmHg) intervals that were normocapnic and isocapnic, and on a separate day completed a time‐matched normoxic control protocol. Prior to (T0), and immediately (T1) and 30 min (T2) following each protocol, EF was assessed via the antisaccade task. Antisaccades require a goal‐directed eye movement (i.e., saccade) mirror‐symmetrical to a target and provide the resolution to detect subtle EF changes. As expected, hypoxic intervals decreased arterial and cerebral tissue O 2 saturation and increased CBF as estimated via near‐infrared spectroscopy and transcranial Doppler ultrasound ( p s < 0.001). In turn, antisaccade reaction times (RT) did not differ between T0 and T1 ( p = 0.29); however, at T2 a reliable RT reduction was observed ( p = 0.004). Notably, cortical hemodynamic changes during the hypoxic intervals did not correlate with the antisaccade RT benefit observed at T2 ( p s > 0.17). Thus, a single bout of IH provided a transient post‐intervention EF “boost” that was not linked to a unitary physiological adaptation to a reduced O 2 environment.