Effects of Hook Maneuver on Oxygen Saturation Recovery After -40 m Apnea Dive-A Randomized Crossover Trial.

To reduce the risk of syncope, trained breath-hold divers (BHDs) use a specialized breathing technique after surfacing called "hook breathing" (HB). It consists of a full inspiration followed by a Valsalva-like maneuver and with subsequent exhalation performed against resistance to generate continuous positive airway pressure during exhalation. This study analyzed the influence of HB on oxygen saturation recovery after a -40 m depth apnea dive in trained BHDs.

Effects of Apnea-Induced Hypoxia on Hypoalgesia in Healthy Subjects.

Introduction: Exercise-induced hypoalgesia is a phenomenon in which exercise bouts induce a reduction in pain sensitivity. Apnea training involves similar characteristics that could potentially induce hypoalgesia.

Objectives: The objectives of this study are to explore the effect of apnea training on hypoalgesia; assess the correlation between conditioned pain modulation (CPM) response and apnea-induced hypoalgesia; and examine the association between hypoalgesia with hypoxemia, and heart rate (HR) during apnea.