This study aims to investigate the acute cognitive and physiological responses to breath-hold diving training in trained female divers. Participants will complete three separate sessions including a control session, a land-based breath-hold training session, and a water-based breath-hold training session in randomized order. Cognitive performance, mood state, heart rate responses, respiratory function, and maximal breath-hold capacity will be evaluated before and after the interventions. The study is expected to improve understanding of how acute apnea-based diving exercises influence cognitive functions and physiological adaptations under different environmental conditions.