How does freediving affect the human body?
Free diving has many physiological effects on the human body, especially as a result of holding the breath for long periods, including.
1- Oxygen Deprivation (Hypoxia):
One of the primary physiological challenges of freediving is the reduction in oxygen levels as a diver holds their breath.
As oxygen is consumed, and carbon dioxide levels rise, the body undergoes a state of hypoxia. The body's response to hypoxia includes increased heart rate, blood pressure,
and a shift in blood flow to vital organs to preserve oxygen.
2- Increased Carbon Dioxide (Hypercapnia):
As a person holds their breath, carbon dioxide levels in the body increase. This leads to a sensation of air hunger, triggering the urge to breathe.
The body's tolerance to elevated carbon dioxide levels varies among individuals and can be trained through specific breath-holding exercises.
3- Blood Shift:
During freediving, a phenomenon known as the blood shift occurs. As a diver descends, blood is shifted from peripheral blood vessels to the chest cavity,
allowing the lungs to collapse without causing barotrauma. This helps conserve oxygen and facilitates greater depths during freediving.
4- Bradycardia (Slowed Heart Rate):
Freediving is associated with a diving reflex, which includes bradycardia—a significant reduction in heart rate. This reflex helps conserve oxygen by minimizing the workload on the heart.
The diving reflex is more pronounced in cold water and varies among individuals.
5- Peripheral Vasoconstriction:
In response to immersion in cold water, the body undergoes peripheral vasoconstriction, where blood vessels in the extremities constrict to preserve heat and redirect blood flow to vital organs.
6- Spleen Contraction:
Freediving can stimulate the spleen to contract, releasing stored red blood cells into circulation. This process, known as splenic contraction,
temporarily increases the oxygen-carrying capacity of the blood, aiding in breath-holding.
7- Barotrauma and Equalization:
Changes in pressure during freediving can lead to barotrauma, where pressure imbalances cause ear and sinus discomfort.
Equalization techniques are essential to balance pressure and prevent injuries, especially during descent.
8- Nitrogen Narcosis:
While not as pronounced as in scuba diving, nitrogen narcosis can occur during freediving at significant depths.
This condition is characterized by an altered mental state, similar to the effects of alcohol intoxication,
due to the narcotic effects of nitrogen under pressure.
* It's crucial for freedivers to undergo proper training to develop breath-holding skills, understand safety protocols, and mitigate potential risks.
Freediving, when practiced responsibly, can offer unique experiences and benefits, but it should be approached with awareness of its effects on the body and the importance of safety measures.