Energy Availability as a Neurocognitive Regulator of Endurance Performance: Integrating Metabolic, Perceptual, and Decision-Making Mechanisms-A Narrative Review.

Endurance performance is regulated through dynamic interactions between physiological capacity, nutritional status, and psychological control processes. While traditional endurance models have emphasized metabolic and cardiorespiratory determinants, growing evidence indicates that energy availability also influences cognitive function, perceived effort, and decision-making during prolonged exercise. This narrative review synthesizes current literature on the interplay between nutritional strategies and psychological regulation in endurance sports, with particular emphasis on low energy availability, carbohydrate availability, mental fatigue, and pacing behavior. Acute and chronic reductions in energy availability are associated not only with endocrine and metabolic disturbances but also with amplified perceived exertion, impaired executive functioning, reduced effort tolerance, and altered risk-related decision-making, even in the absence of overt physiological failure. Carbohydrate availability emerges as a central modulator operating through both peripheral mechanisms (substrate supply and glycogen preservation) and central neurocognitive pathways influencing perception, motivation, and fatigue regulation. Hydration status, caffeine ingestion, and gastrointestinal tolerance further interact with perceptual and cognitive processes to shape real-time pacing and endurance sustainability. Integrating sport nutrition and sport psychology provides a unifying framework for understanding endurance regulation as a multilevel process linking metabolic state to perceptual experience and behavioral decision-making. From an applied perspective, optimizing endurance performance requires maintenance of adequate long-term energy availability, strategic carbohydrate periodization aligned with training demands, and systematic monitoring of perceived effort alongside physiological load. Future research should prioritize interdisciplinary, ecologically valid designs combining metabolic, perceptual, and cognitive measurements, supported by wearable and data-driven technologies capable of capturing real-time endurance regulation. Bridging nutritional and psychological mechanisms within a unified conceptual model offers a stronger scientific basis for improving performance sustainability while safeguarding athlete health in modern endurance sport.