Adrenal Glands Function and Orthostatic Intolerance in Athletes: Implications for Sports Performance and Training Management

Orthostatic intolerance (OI) encompasses a spectrum of conditions characterized by impaired cardiovascular regulation upon standing, leading to symptoms such as dizziness, fatigue, lightheadedness, syncope, and reduced exercise tolerance. While frequently studied in clinical settings, OI remains underrecognized in athletes, where its impact on performance, recovery, and well-being may be substantial. This narrative review examines the physiological basis of OI with a particular focus on adrenal gland function—namely the secretion of cortisol, aldosterone, and catecholamines—and their role in maintaining orthostatic stability. It explores how factors specific to athletic populations, such as intense training intensity, dehydration, and relative energy deficiency (RED-S), can impair autonomic and adrenal responses. Diagnostic strategies including orthostatic testing and hormonal profiling are discussed, along with the need for dynamic assessments that reflect functional hormone reserve. Management options range from non-pharmacologic interventions like fluid and salt optimization to pharmacological support in severe cases. The article also highlights the importance of athlete education, training periodization, and coach involvement. Finally, future research priorities are outlined, including sex-specific hormonal dynamics, wearable monitoring, and early biomarkers of dysregulation. Increasing awareness of OI in athletic settings and its hormonal underpinnings can contribute to more effective detection, prevention, and treatment strategies—ultimately improving health outcomes and sustaining high performance.