5 Scientific Reasons Breath Holding Enhances Performance and Builds Resilience
Breath holding — also known as voluntary apnoea, the practice of intentionally holding the breath after inhalation or exhalation — is gaining attention well beyond the freediving world. Emerging research and applied training demonstrate that strategic breath-hold practices can significantly enhance sports performance and foster greater physical and mental resilience.
After guiding thousands of people through breathing workshops and trainings, and working with On’s top sponsored global athletes, we have witnessed the profound impact of this practice firsthand. Breath holding is not only a powerful tool for building physical resilience and improving performance, but also a possible pathway to deeper self-awareness. It enhances the communication between mind and body, helping individuals shift out of overthinking and reconnect with their inner state.
By intentionally holding the breath, we offer the nervous system a reset — often allowing people to emerge from the practice feeling calmer, more grounded, and mentally clearer, while also supporting faster recovery and a renewed sense of vitality and energy.
The practice of breath holding offers a range of potential benefits, including improved physiological function, enhanced stress adaptation, and greater overall resilience across a wide range of individuals, including both professional and recreational athletes.
It is important to note that there are various breath-holding techniques, and selecting the appropriate method depends on factors such as the desired outcome, individual health status, and CO₂ tolerance. As a general recommendation for initial practice, we advise starting with breath-holding techniques that do not involve controlled hyperventilation. It is important to build the practice gradually, allowing the body and nervous system to adapt safely over time.
1. Boosted Red Blood Cell Availability
Breath holding initiates a two-phase adaptation to enhance red blood cell availability and oxygen transport:
First, spleen contraction occurs as an acute response to apnoea-induced hypoxia. The spleen releases a reserve of red blood cells into circulation, leading to a temporary increase in hemoglobin concentration and improved oxygen-carrying capacity (Bakovic et al., 2003; Bouten et al., 2024)
Second, repeated and sufficiently intense breath-hold exposure can stimulate the release of erythropoietin (EPO), a hormone produced by the kidneys in response to low oxygen levels. EPO acts on the bone marrow, promoting the production and release of new red blood cells. This longer-term adaptation may improve aerobic performance by increasing the blood’s overall oxygen-carrying capacity. However, current evidence suggests that a significant EPO response requires a sufficiently high hypoxic dose and is more consistently observed in experienced breath-hold practitioners (Bouten et al., 2024).
2. Human Growth Hormone (HGH) Release
Intermittent hypoxia, as induced by controlled breath holding, has been associated with stimulation of human growth hormone (HGH) release. HGH plays a vital role in tissue repair, muscle growth, fat metabolism, and overall recovery. While preliminary findings are promising, further studies are needed to confirm the specific effects of breath holding on HGH levels (Filopoulos, Cormack, & Whyte, 2017).
3. Building CO₂ Tolerance
The urge to breathe is primarily driven by rising CO₂ levels in the blood, not by falling oxygen levels. Breath holding gradually builds the body’s tolerance to higher concentrations of CO₂, leading to improved control over the respiratory drive, better acid-base balance, and greater resilience under both physical and psychological stress. Over time, this practice serves as a physiological training method to slow down breathing patterns naturally, supporting more efficient and calmer respiration at rest and during effort.
Building CO₂ tolerance is valuable not only for athletic and endurance performance but also for enhancing stress management, emotional regulation, and overall resilience in daily life (McKeown, 2021; Bouten et al., 2024)
4. Increasing Diaphragm Strength and Lung Capacity
Breath-hold training serves as a unique form of isometric exercise for the diaphragm and accessory respiratory muscles. Over time, this practice can lead to improved respiratory efficiency, stronger inspiratory and expiratory muscles, and enhanced breath control during both exercise and recovery phases. Additionally, breath-hold training may contribute to increased lung capacity, allowing for greater oxygen intake and utilization.
Research has shown that intermittent breath-hold training can significantly improve respiratory function, lung volumes, and the strength of the breathing muscles, particularly in competitive athletes (Cross et al., 2013).
5. A Calmer, More Focused, and Resilient Mind
Beyond physical adaptations, breath holding has profound effects on the nervous system. It often activates the parasympathetic nervous system after an initial sympathetic spike, leading to increased heart rate variability (HRV), improved emotional regulation, and sharper mental clarity (Chen et al., 2014).
Practitioners often report feeling more centered, clear-headed, and present after breath-hold sessions — effects that extend into training, competition, and daily life. By improving emotional regulation and nervous system balance, breath holding also contributes to building greater psychological resilience, helping individuals remain composed and focused under pressure.
Conclusion
Breath-hold training, once mainly associated with freediving, is now emerging as a powerful tool for enhancing physical performance, accelerating recovery, and building greater resilience — both mentally and physically. Research shows how strategic breath holds improve oxygen transport, increase stress tolerance, and sharpen the mind-body connection.
Yet beyond the science, what we witness time and time again in our keur breathwork teacher trainings and workshops is something deeper: a shift. Participants leave not only breathing differently but living differently — with a calmer presence, more clarity under pressure, and a renewed sense of inner strength.
In a world that often pulls us outward, breath-hold training invites us back into ourselves — steady, focused, and alive. If you’re curious to learn more, we’ve just launched our new Sports Performance + Resilience Workshop — designed for professional and recreational athletes, sports teams, and anyone ready to explore deeper.
