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Updated: Jun 21, 2026
09:54
A Model to Simulate Clinically Relevant Hypoxia in Humans
Published on: December 22, 2016
Cardiovascular changes during maximal breath-holding in elite divers
Pietro Guaraldi1, Maria Serra, Giorgio Barletta
1Dipartimento di Scienze Neurologiche, Alma Mater Studiorum-Università di Bologna, Italy. pietro.guaraldi@unibo.it
Summary
Elite divers experience a sudden blood pressure surge during breath-holding, indicating a defense mechanism overriding the diving reflex to prevent hypoxic damage and loss of consciousness.
Area of Science:
- Physiology
- Human Performance
- Cardiovascular Research
Background:
- The mammalian diving reflex is a well-documented physiological response to breath-holding.
- Elite breath-hold divers push physiological limits, potentially revealing novel responses.
Purpose of the Study:
- To investigate cardiovascular changes during maximal breath-holding in elite divers.
- To identify if a defense reaction occurs during the "struggle" phase of apnea.
Main Methods:
- Six healthy elite breath-hold divers participated in maximal breath-holding maneuvers.
- Cardiovascular parameters were monitored, particularly during different phases of the dive.
Main Results:
- An initial "diving response" was observed, characterized by specific cardiovascular changes.
- A sudden and severe rise in blood pressure occurred during the "struggle" phase.
Conclusions:
- The observed blood pressure surge suggests a defense reaction overriding the diving reflex.
- This reaction may aim to mitigate hypoxic damage and prevent blackout during extreme apnea.
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