Breath for battle: Enhancing fighter pilot performance through respiratory muscle training – A narrative review

Military aviators are exposed to extreme physiological stressors, including high gravitational acceleration (+Gz), hypoxia, and increased ventilatory workload, factors that impair respiratory and cognitive function. These conditions may accelerate diaphragm fatigue, reduce G-tolerance, and elevate the risk of in-flight performance decrement. Respiratory Muscle Training (RMT) has emerged as a promising non-pharmacological countermeasure to strengthen inspiratory muscles, enhance ventilatory efficiency, and support psychophysiological resilience. This narrative review synthesizes current evidence from aerospace physiology, elite sport, and hypoxia-based research. While findings in aviation-specific populations remain limited, studies in analogous groups, such as endurance athletes, high-altitude soldiers, and divers, offer valuable physiological insight. Across different RMT modalities (e.g., threshold loading, resistive breathing, isocapnic hyperpnea), reported outcomes include gains in inspiratory muscle strength (PImax), oxygen uptake (VO 2 max), and ventilatory efficiency; however, the heterogeneity of protocols and populations warrants cautious interpretation of quantitative ranges (e.g., 20–45% PImax improvements; 4–12% VO 2 max gains). Emerging data also suggest cognitive benefits of RMT under hypoxic or high-G conditions, potentially through attenuation of the respiratory muscle metaboreflex and improved cerebral oxygenation. Although more aviation-focused trials are needed, RMT shows promise as a low-risk, portable, and scalable intervention to enhance operational performance, readiness, and resilience in extreme environments.