Advanced Freediving Physiology

Seminar

Explore the advanced physiological adaptations that make deep freediving possible. This seminar examines equalization techniques, the diving response, breath-hold physiology, hypoxia, lung injuries, rescue procedures, and the physiological challenges encountered in deep and record freediving.

The Moves for clearing the ears

The differences in equalizing the ears between the 0 -10 meter depth zone and the 10 – 20 m zone.
The selection of the best suitable ear clearing method for a dive to 20 meters:
- 1. The Valsalva equalization.
- 2. The Frenzel and the Frenzel mouth-fill equalization.
- 3. The “Hands Free” (or Voluntary Tube Opening – VTO) equalization.
Underwater exercises: practice dives for the ear clearing methods.
Ear injuries
- Barotrauma of the middle or inner ear.
- The Eardrum Rupture.

The Diving Reflexes: The Human Body’s Diving Response in Freediving

The diving reflex (auto – equalization of the lungs).
- Peripheral vasoconstriction.
- The “blood shift” (Intrathoracic blood concentration).
- Reflex bradycardia.
- Heart rate and breath-holding.
- Diving reflex and training.
Lung Squeeze – pulmonary barotrauma in freediving.
- Lung descent barotrauma (injury from excessive compression of the lungs).
- Lung barotrauma of ascent – Lung over-expansion injuries.
- Useful tips on avoiding a lung squeeze.
- Lung packing: a dangerous method.
The immersion diuresis.
The reflex of spleen contractions and the increase in red blood cell count.
The body’s “diving response” in freediving.

Respiratory movements and breathing

Respiratory volumes and capacities.
- The dead space.
The air volume of breathing: calm breathing, normal breathing and deep breathing.
– The full breath and its three volumes: diaphragmatic, lateral and high thoracic breathing.
The value of diaphragmatic breathing in freediving.

Apnea

Apnea: The breath-hold physiology.
- Conversion of carbon dioxide (CO2) gas to bicarbonates during the diving phase.
- Relief from carbon dioxide (CO2) in the ascent phase.
- The “wave” of release of carbon dioxide (CO2) during the first minute after ascent.
The single “biochemical formula” of apnea duration (all apnea factors).
- The idea of unification of all apnea factors into a single formula.
- The single biochemical formula of apnea and its core: The “carbon dioxide (CO2)”.
The body’s ten-minute recovery time between two freedives.
The biochemical effects of hyperventilation.
- Hypocapnia and hypercapnia.
- Hypocapnia and respiratory alkalosis.
- Hypercapnia and respiratory acidosis.
Adaptation to the large load of carbon dioxide (adaptation to hypercapnia).
The difference between hyperventilation and hyper-oxygenation.

Hypoxia – Shallow Water Blackout

Hypoxia and hypoxic state.
The symptoms of a hypoxic state in general (without leading to hypoxia or before leading to hypoxia).
- The diaphragmatic spasms.
The simultaneous symptoms of hypoxia (shallow water blackout): “samba” – muscle spasms, muscle tightening and possible involuntary exhalation.
The mechanism of hypoxia – when the freediver is threatened by hypoxia.
- The establishment mechanism of hypoxia.
- Depletion of carbohydrates, combustion of lipids and inducement of hypoxia.
The hypoxia (or shallow water blackout) “barrier” of 7 or 10 meters during ascent.
Before hypoxia (blackout): no warning symptoms
– After the first hypoxia: the body’s familiarization with the easy and frequent inducement of hypoxia.
The avoidance of hypoxia: the valuable tips of world freediving champions.

Rescue Techniques for a Hypoxic Victim

The safety monitoring of each dive by the dive buddy.
- The difficulty in early recognition of a blackout.
The rescue of a hypoxic diver on the surface.
The rescue of a blacked out diver sinking to the seabed.
Care of the hypoxic diver after his rescue.

Pathophysiology of Record Freediving

The freediving decompression sickness.
The nitrogen narcosis and the narcotic effect of gases in deep and record freediving.

Learning outcomes

Participants will learn:

Advanced equalization techniques including Valsalva, Frenzel, Mouth-Fill, and VTO
How to select the most suitable equalization method for different depths
Recognition, prevention, and management of ear barotrauma
The physiological effects of the mammalian diving response
The mechanisms of blood shift, bradycardia, and peripheral vasoconstriction
Causes, prevention, and management of lung squeeze and pulmonary barotrauma
Advanced respiratory physiology and breathing mechanics
The biochemical foundations of breath-hold performance
The effects of carbon dioxide, oxygen, hyperventilation, and hypercapnia
Recognition and prevention of hypoxia, LMC, and blackout
Advanced rescue procedures for hypoxic and unconscious freedivers
The physiological challenges of deep and record freediving, including decompression sickness and nitrogen narcosis

This seminar is designed for experienced freedivers who wish to understand the science behind deep diving performance and safety. It provides the physiological knowledge required to dive deeper, train more effectively, and better recognize and manage the risks associated with advanced freediving.