Iron Status, Muscle Oxygenation and Performance in Female Athletes During Repeated-Sprint Training in Hypoxia.

Repeated-sprint training in hypoxia (RSH) is widely used by team-sport athletes to enhance repeated sprint ability (RSA), often achieving greater performance gains at sea level than normoxic equivalent. While RSH has been well studied in males, its impact on females remains underexplored, despite biological differences that may alter exercise responses. Female athletes face unique physiological challenges (e.g. hormonal fluctuations and menstruation), which increase iron demands. Iron deficiency is common in this population, with implications for both endurance and team-sport athletes. As team sports rely on both anaerobic and aerobic energy systems, driven by iron-dependent metabolic pathways, understanding the role of iron in repeated-sprint exercise is essential. RSA relies on effective reoxygenation of active musculature between sprints to support rapid phosphocreatine and adenosine triphosphate resynthesis. Given iron's essential role in oxygen transport and mitochondrial energy production, compromised iron status may impair muscle oxygenation and impair RSA, especially under hypoxic conditions (i.e. RSH) where oxygen availability is already limited. To maximise RSA outcomes for female athletes, it is necessary to understand how iron status influences their responses to RSH. Accordingly, this narrative review explores the relationship between iron status and muscle oxygenation kinetics during repeated-sprint exercise in hypoxia among female athletes and its effects on RSA, and provides recommendations to guide future research and training practices.