Author(s): SAROLA GASSIOT, J., IRURTIA A., DALMAU-SANTAMARIA I., RODRÍGUEZ-ZAMORA L., Institution: FUNDACIÓ TECNOCAMPUS (MATARÓ, BARCELONA) SPAIN, Country: SPAIN, Abstract-ID: 1494

INTRODUCTION:
Competitive freediving involves repeated voluntary breath-holding across pool and open-water disciplines, during which hypoxic events of varying severity may occur (Mulder et al., 2026). Identifying lifestyle-related factors potentially associated with these events is relevant for diver safety. Dietary habits may influence metabolic responses and hypoxic tolerance (Deb et al., 2016); however, evidence in competitive freediving remains limited. Therefore, this study aimed to explore the relationship between dietary habits and self-reported hypoxic events, including blackout, in Spanish competitive freedivers.
METHODS:
A cross-sectional observational study was conducted in 20 women (age 39.7±9.1years, BMI: 22.9±3.1 kg·m⁻²) and 52 men (age 41.9±8.6 years, BMI: 23.5±2.8 kg·m⁻²), all competitive freedivers holding an official federation license in Spain. A validated 17-item questionnaire and an adapted food frequency questionnaire (FFQ) to the Spanish population (PREDIMED), including 140 items plus vitamin/mineral supplements (Estruch et al., 2013), were used, along with specific questions on alcohol consumption patterns. Participants represented different competitive levels and disciplines performed in both pool and open-water settings. History of hypoxic events during the sporting career was self-reported and categorized by severity (dizziness, loss of motor control/samba, blackout), with participants classified according to the most severe event experienced. Dietary habits were grouped into broad categories reflecting overall diet quality based on consumption frequency of selected food groups, and dietary pattern scores were calculated as mean intake frequency. Differences in hypoxic event occurrence and severity across dietary categories were analyzed using chi-square or Fisher’s exact tests (p<0.05).
RESULTS:
Hypoxic events during the sporting career were reported by 21 participants, with varying severity [dizziness = 18%, loss of motor control (samba) = 5.6%, blackout = 8.3%]. No statistically significant differences in the prevalence or severity of hypoxic events were observed across dietary habit categories (p>0.05). Dietary scores indicated generally moderate-to-high consumption of nutrient-dense food groups, including fruit and vegetables (51.4%) and protein-rich foods (50%), while lower proportions of participants were classified in the high consumption category for ultra-processed foods (5.6%) and alcohol (1.4%).
CONCLUSION:
In this sample of Spanish competitive freedivers, dietary habits were not associated with the occurrence or severity of self-reported hypoxic events. Further studies including larger samples and objective physiological monitoring are needed to better understand factors related to hypoxia-related risk in competitive apnea.