Bikrom Maity, Priya Nandy
Iron deficiency (ID) remains a pervasive yet frequently overlooked "silent performance killer" in female athletes. Despite its prevalence, it often remains undetected due to a traditional clinical over-reliance on hemoglobin (Hb) levels as the primary diagnostic criterion. This review synthesizes current physiological and laboratory research to demonstrate that standard hematological reference ranges, calibrated for the sedentary general population, fail to account for unique athlete-specific mechanisms. Key factors such as foot-strike hemolysis—the mechanical rupturing of red blood cells during high-impact activity—and exercise-induced gastrointestinal ischemia significantly accelerate iron turnover. Furthermore, the discovery of the hepcidin-mediated iron blockade has revolutionized our understanding of iron homeostasis in sports. Post-exercise inflammation, characterized by elevated Interleukin-6 (IL-6), triggers a spike in hepcidin, which degrades ferroprotein and effectively halts iron absorption for several hours post-training. This dynamic makes traditional "once-off" blood testing potentially misleading. Consequently, this review argues for a critical diagnostic shift in sports medicine toward more sensitive biomarkers. By prioritizing serum ferritin (using an athletic-specific threshold of <35 ng/mL) and soluble transferrin receptor (sTfR)—which remains unaffected by acute inflammation—medical lab professionals can accurately identify non-anemic iron deficiency (NAID). Identifying NAID is essential, as even in the absence of clinical anemia, depleted iron stores compromise mitochondrial cytochromes and myoglobin, leading to reduced VO2max and impaired aerobic capacity. Re-evaluating iron status through these advanced laboratory markers is vital for optimizing the health, recovery, and competitive edge of female athletes. Keywords: Iron Deficiency, Female Athletes, Serum Ferritin, Hepcidin, Sports Hematology, Non-Anemic Iron Deficiency (NAID), Soluble Transferrin Receptor.