Iron regulation and absorption in athletes: contemporary thinking and recommendations

Abstract

Purpose of review This review examines recent developments in our understanding of iron regulation/absorption around exercise, with specific attention paid towards the female athlete. Recent findings Building on the well accepted knowledge that hepcidin concentrations increase in the 3–6 h period following an acute bout of exercise, recent studies have shown that this links to a reduced fractional iron absorption from the gut during feedings provided 2 h postexercise. Further, a window of enhanced iron absorption has recently been identified to occur 30 min either side of exercise commencement/completion, which allows for strategic iron intake to optimize absorption around exercise. Finally, there is burgeoning evidence to show that iron status and iron regulation change throughout the menstrual cycle and with hormonal contraceptive use, which could have implications for iron status in female athletes. Summary Exercise can affect iron regulatory hormone activity, which subsequently impairs iron absorption, potentially contributing to the high rates of iron deficiency seen in athletes. Future research should continue to examine strategies to optimize iron absorption, with consideration to the timing, mode and intensity of exercise, the time of day, and in females, the menstrual cycle/menstrual status.

The Physiological Requirements of and Nutritional Recommendations for Equestrian Riders

“…As many equestrian participants are female, this strongly suggests iron is a micronutrient of concern for equestrians and supporting practitioners, with annual monitoring of iron status recommended as a minimum practice. Along with the potential for menstrual iron losses, athletes undertaking large riding volumes may have a lowered energy availability, and postexercise-inflammatory and/or hepcidin responses may present with varying degrees of iron depletion or post-exercise iron uptake [183][184][185]. Oral contraceptive use does not appear to alter these factors [186].…”

Prevalence of iron-deficient but non-anemic university athletes in Japan: an observational cohort study

“…One primary mechanism is insufficient iron intake, which can be exacerbated by the increased demand of athletic training [ 3 ]. Additionally, athletes may experience iron malabsorption in the gut due to factors like inflammation, which is often a result of intense physical activity [ 4 ]. Inflammation can increase levels of hepcidin, a key regulator of iron homeostasis.…”

Editorial: micronutrients and functional foods

“…Peeling et al [2] presents a state-of the art review on the important topic of iron in sports. The attainment and maintenance of adequate iron stores is critically important for an athlete's performance.…”