Predicting Performance in Competitive Apnoea Diving. Part I - Static Apnea
Authors: Erika Schagatay
DOI / Source: https://pubmed.ncbi.nlm.nih.gov/22753202/
Date: 01 June 2009
Reading level: Intermediate
Why This Matters for Freedivers
Static apnea performance isn’t “just willpower”. This paper breaks it down into trainable pieces—how much oxygen you can store, how slowly you burn it, and how well you handle the discomfort and physiology of rising CO₂ and falling O₂. If you’re training breath-holds, it also highlights why some methods work, why others carry safety risks, and which factors are more about smart preparation than brute force.
Synopsis
Since competitive freediving began, athletes have repeatedly smashed what scientists once thought were “hard limits.” So what actually sets the limit in a static breath-hold, and what predicts who will do well?
This review explains static apnea as a simple equation with three big parts:
1) Total gas stores (how much O₂ you start with, and how much CO₂ you can buffer).
The lungs matter—bigger lung volumes can buy real time, especially when your body is relaxed and oxygen use is low. The review also points to blood as a major “tank”: hemoglobin carries oxygen, and changes in circulating hemoglobin (including the spleen squeezing and releasing extra red blood cells) can add a temporary boost during repeated apneas. The author discusses why elite divers often show unusually large lung volumes and strong spleen responses, and whether this is selection (built that way) or training (adapted).
2) Tolerance to asphyxia (how you handle rising CO₂, acidity, and falling O₂).
A breath-hold usually has a calmer “easy phase” followed by the “struggle phase,” when the urge to breathe ramps up and contractions appear. The paper explains that divers often tolerate higher CO₂ and lower O₂ than non-divers, partly because their ventilatory response to CO₂ can be blunted with training and experience. This is a double-edged sword: it can help performance, but it also increases the risk of pushing into dangerous hypoxia if judgment slips.
3) Metabolic rate (how slowly you spend your oxygen).
In static, the big performance advantage often comes from using less oxygen than normal resting levels. The diving reflex (bradycardia and peripheral vasoconstriction) helps, but so do “soft skills” like relaxation, staying warm, and reducing unnecessary movement and mental arousal. The review emphasizes that elite divers don’t just “tough it out”—they learn to stay efficient and calm, keeping oxygen consumption low for longer.
Finally, the paper discusses common techniques used by divers to increase time—like specific breathing strategies and lung packing (glossopharyngeal insufflation). It notes that these can extend apnea by increasing starting lung volume, but they can also create problems (for example, fainting risk if done badly, or cardiovascular strain), so the safest gains come from structured training, smart pacing, and a strong safety culture.
Abstract
Competitive apnea records have improved rapidly, raising the question of what factors determine the ultimate limits of human breath-hold performance and which predictors best explain elite results. In static apnea, performance depends mainly on three interacting components: total body gas storage (in lungs, blood, and tissues), tolerance to asphyxia (rising CO₂/acidosis and falling O₂), and metabolic rate during the breath-hold. These main components can be further divided into physiological and psychophysiological factors such as lung volume and breathing techniques, splenic contraction and hemoglobin availability, ventilatory sensitivity to CO₂, and the ability to reduce oxygen consumption through the diving response and relaxation. The review outlines which factors appear associated with top performance, which may be influenced by training, and how current strategies suggest that static apnea duration can be extended further—while recognizing important safety considerations.