The International Association for the Development of Apnea -AIDA- has funded a scientific study published in the European Journal of Applied Physiology (Springer) examining the physiological effects of repeated deep-water training in elite freedivers. Conducted in Dahab (Egypt), the research identifies a progressive inflammatory and oxidative response in the body after several consecutive deep dives, providing new insight into how the human organism reacts to one of the most demanding environments in sport.

Beyond its role as a governing body and organiser of international competitions, AIDA also supports initiatives focused on athlete safety and health. The research forms part of that institutional approach, aimed at anticipating risks and expanding scientific knowledge in a discipline where the physiological limits of the human body are constantly explored. The study addresses several key areas, including observation in real training conditions, the assessment of decompression sickness risk, the development of further scientific research and the update of medical standards for depth competitions.

A pioneering study conducted in real training conditions

The research, titled “Cumulative Oxidative and Inflammatory Responses to Repeated Depth Training in Breath-Hold Divers: A Multiparametric Field Study”, represents one of the first scientific efforts to analyse the cumulative effects of depth-training in freediving directly in the environment where the sport is practiced. Unlike earlier laboratory-based studies, the work was carried out in real training conditions with 24 experienced freedivers who performed repeated dive sessions over two and three consecutive days.

Researchers evaluated several physiological indicators before and after the dives in order to detect possible stress responses in the body. Among them were inflammatory markers measured in saliva, including interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α), as well as reactive oxygen species (ROS) associated with oxidative stress. The results showed significant increases in these parameters following the deep dive sessions, suggesting that repeated training at depth may generate cumulative physiological responses in the diver’s body.

Microbubbles and decompression sickness: what the study shows

The study also incorporated ultrasound techniques to detect possible vascular gas emboli, a method that allows researchers to observe the presence of microbubbles in the bloodstream. This type of analysis is particularly relevant for assessing the potential risk of decompression sickness, an issue that has attracted growing attention in the medical field of deep freediving.

In this case, researchers did not observe significant changes in the presence of microbubbles after the training sessions. This finding suggests that the inflammatory responses detected may occur independently of the classical mechanisms associated with decompression. The study also examined lung aeration through ultrasound and assessed participants’ hydration levels, identifying a temporary increase in pulmonary signals after diving that returned to baseline levels within less than an hour.

New research and updated medical protocols

The study funded by AIDA forms part of a broader scientific programme led by the organisation’s medical and science committee. Within this framework, a new publication is already in preparation based on data collected during the AIDA Depth World Championships held in Cyprus, aiming to provide further understanding of the mechanisms that may lead to injuries in freediving and to analyse symptoms affecting both the respiratory system and the central nervous system.

At the same time, the medical committee has updated several key reference documents for medical support in depth competitions. These include the revision of the recommended medical equipment list for freediving events and the update of the document outlining medical contraindications for freediving practice, prepared with the participation of specialists from the United States, Switzerland, Russia, Belgium, and Italy. The organisation has also released specific medical recommendations for world record attempts in the Variable Weight -VWT- discipline, defining requirements for medical team composition, emergency evacuation planning, pre-attempt medical assessments and athlete insurance coverage.