This retrospective observational study evaluates physiological and cognitive changes following a series of 60 hyperbaric oxygen therapy (HBOT) sessions in healthy individuals. Participants underwent treatment five days per week, each session included 90 minutes exposure to 100% oxygen at 2ATA with a five-minute air break every 20 minutes. Pre- and post-treatment data include cardiopulmonary exercise testing (CPET) and standardized cognitive assessments. The study aims to characterize associations between changes in cardiorespiratory fitness and cognitive performance following repeated HBOT exposure in a real-world clinical cohort