Iron metabolism in athletes – achieving a gold standard

Abstract

Iron is an important mineral element required for diverse life processes. Its metabolism is almost synonymous to erythrocyte maintenance, erythropoiesis and erythrophagocytosis. Consequently, exercise exertion impacts significantly on red cell haematology. Here, the interactions between exercise and erythropoiesis are explored. Hepcidin, the peptide hormone that regulates systemic iron metabolism, decreases in response to erythropoiesis by facilitating increased iron efflux from ferroportin into circulation. However, during exercise, there is an alarming increase in the expression of hepcidin resulting in a negative iron balance in athletes. In this review, the confounding cause and effect scenarios of exercise, athlete training and haematology and hepcidin interactions are discussed.

Early changes of the anemia phenomenon in male 100-km ultramarathoners

“…Although further direct evidence is needed, our results are compatible with the hypothesis that oxidative stress response plays a role in sports anemia. 6,10,12 Exercise-induced hemolysis is a widely observed phenomenon during long-distance running. An athlete's typical blood profile includes a decrease of haptoglobin and an increase of plasma Hb levels.…”

“…9,10 It has been suggested that the lasting high levels of erythropoietin (EPO) may promote an increase in red cell mass to maintain tissue oxygen levels after a marathon run. 11,12 To our knowledge, there has been no published report that describes the overall hematological, urinary, and fecal changes of the anemia phenomenon in Asian male ultramarathoners after a 100-km (62.5-mile) ultramarathon event. We therefore analyzed these athletes' blood specimens for anemia parameters, oxidative stress cytokines, hemolysis markers, and iron levels.…”

Timing of post-exercise carbohydrate ingestion: influence on IL-6 and hepcidin responses

“…Peak post-exercise hepcidin levels are usually attained approximately 3 h following exercise, subsequent to significant elevations in IL-6 (Peeling et al 2009a;Sim et al 2012;Badenhorst et al 2014). Elevations in hepcidin levels in the post-exercise recovery period have been suggested as a potential mechanism for altered iron metabolism within athletes (Roecker et al 2005;Peeling et al 2008;Latunde-Dada 2013), due to the hormone's influence on the Fpn cellular iron export channels located on the basolateral intestinal enterocytes and macrophage cell surface (Nemeth et al 2004b). Consequently, an individual may be susceptible to a reduction in iron recycling and iron absorption during the post-exercise period (Peeling et al 2009a).…”

Changes in iron metabolism during prolonged repeated walking exercise in middle-aged men and women

“…The rise in hepcidin levels causes a reduced influx of iron in the circulation through increased degradation of ferroportin (Nemeth et al 2004), which might result in iron deficiency in the long run (Ganz and Nemeth 2006; Latunde-Dada 2013). Next to this, certain types of exercise can lead to foot strike haemolysis.…”