Breath-hold diving (BHD) represents a unique human behavior that challenges multiple physiological systems through exposure to hypoxia, hypercapnia, and increased ambient pressure. While BHD was traditionally studied in elite athletes and specific populations, voluntary apnea can also provide a powerful model for exploring acute and chronic human adaptations to oxygen deprivation in the absence of pathology. The complex, coordinated responses involving cardiovascular, respiratory, muscular, and autonomic systems offer a unique window into human physiological plasticity and resilience. Breath-hold diving also offers a natural model of intermittent hypoxia that is gaining interest in clinical research. The repeated exposure to controlled oxygen deprivation appears to induce protective adaptations in multiple organ systems, which could be leveraged to improve outcomes in various pathophysiological states, including cardiovascular disease, chronic hypoxia, and neurodegenerative conditions. Furthermore, the study of BHD may contribute to optimizing human performance and safety in extreme environments such as high altitude, underwater exploration, and aerospace contexts.

This Research Topic aims to deepen our understanding of the biological and physiological mechanisms underlying breath-hold diving, focusing on both short-term responses and long-term adaptations associated with repeated apnea exposure. Our goal is to explore how these mechanisms can inform broader questions in integrative human physiology, as well as inspire potential clinical applications in areas such as ischemic preconditioning, metabolic disorders, and pulmonary or cardiovascular rehabilitation.

We encourage contributions that investigate:
• Cardiovascular and hematological responses during and after apnea, including blood redistribution and spleen contraction;
• The diving reflex and autonomic nervous system regulation;
• Cerebral oxygenation and brain tolerance to intermittent hypoxia;
• Mitochondrial and metabolic adaptations in skeletal muscle and other peripheral tissues;
• Genetic, epigenetic, and environmental factors influencing individual variability in apnea tolerance;
• Training protocols, safety strategies, and performance optimization in freediving;
• Comparative and evolutionary insights into human breath-hold capacity;
• Translational models that apply BHD-derived mechanisms to clinical or therapeutic contexts.

This Research Topic welcomes original research articles, clinical studies, mechanistic in vivo and in vitro models, as well as comprehensive reviews. We aim to build a multidisciplinary collection that highlights BHD not only as a sport or cultural practice but as a valuable physiological paradigm. By integrating knowledge from exercise science, environmental physiology, neurobiology, and medicine, this topic seeks to advance our understanding of how the human body senses, responds to, and adapts under the constraints of voluntary hypoxia.

This collection is guest-edited by Dr. Danilo Cialoni (Università San Raffaele Di Roma, Rome, Italy, and Apnea Academy Research, Padua, Italy), Prof. Gerardo Bosco (University “G. d'Annunzio” of Chieti-Pescara, Chieti, Italy), and Dr. Andrea Brizzolari (University of Milan, Milan, Italy).

Are you interested in contributing a manuscript to this Research Topic?

Breath-Hold Diving: Biological and Physiological Mechanisms, Adaptations, and Clinical Perspectives