Incidence of ID and IDA in athletes – Iron Will
Why Iron is important for athletes?
Iron is an important element that makes up the heme molecules of hemoglobin (Hb) within red blood cells, allowing for oxygen transportation and utilization [3]. During anemia, defined as a deficiency of red blood cells, a decrease of Hb impairs oxygen delivery to the tissues, predisposing to performance decrements despite a compensatory increase of cardiac output [4].
Iron deficiency and Iron deficiency anemia in athletes
Endurance athletes are often thought to be at an increased risk of ID and anemia. Possible mechanisms for ID and IDA include intravascular/foot-strike hemolysis [3-5] ischemia to the viscera [6-7] or frequent non-steroidal anti-inflammatory drug use [7] which may promote gastric lesions [6] loss of iron through urine caused by renal ischemia [4] and iron losses through sweat.
It suggests that the increased training volume, or multiple high-intensity workouts within the same day could be blocking iron absorption [7] inadequate iron intake combined with extremely high levels of training, causing increased inflammation, intravascular hemolysis, ischemia to visceral and kidney tissues, and loss through sweat, could explain this difference.
Possible cause if ID/IDA in athletes
Iron supplementation in Athletes
Verdon et al [2,4] demonstrated that nonanemic women with sFe < 50 ug/L improved mood and fatigues with iron supplementation, demonstrating that the women could likely benefit from additional iron.
Oral iron supplementation is often necessary for the prevention of IDA, however, lower doses (<60mg/d) taken on alternate days, and preferably in the morning before training may optimize iron absorption and limit gastrointestinal damage [7,10].
Incidence in Athletes
The prevalence of ID in endurance athletes is variable, with 20% to 50% of female athletes presenting with low iron (5,11,12) and 0% to 17% of male athletes presenting with low sFe [3].
Iron deficient anemia remains fairly infrequent in the sports literature, with up to 10% to 15% of female athletes having IDA, but with males rarely presenting [8].
The incidence of IDA occurred primarily in triathletes, as 20% of the FT and 25% of the MT had at least 1 occurrence of IDA [3].
References
- Mountjoy M, Sundgot-Borgen J, Burke L, et al. The IOC consensus statement: beyond the female athlete Triad—relative energy deficiency in sport (RED-S). Br J Sports Med. 2014;48:491–497.
- Smith DJ. A framework for understanding the training process leading to elite performance. Sport Med. 2003;33:1103–1126
- Rowland T. Iron deficiency in athletes: an update. Am J Lifestyle Med.2012;6:319–327.
- Clenin GE, Cordes M, Huber A, et al. Iron deficiency in sports—defini-tion, influence on performance and therapy. Swiss Med Wkly. 2015;145:1–15
- Shaskey DJ, Green GA. Sports haematology. Sport Med. 2000;29:27–38
- Reinke S, Taylor WR, Duda GN, et al. Absolute and functional irondeficiency in professional athletes during training and recovery. Int JCardiol. 2012;156:186–191.
- Burden RJ, Pollock N, Whyte GP, et al. Effect of intravenous iron onaerobic capacity and iron metabolism in elite athletes. Med Sci SportExerc. 2015;47:1399–1407.
- Stewart JG, Ahlquist DA, McGill DB, et al. Gastrointestinal blood lossand anemia in runners. Ann Intern Med. 1984;100:843–845.
- Coates A, Mountjoy M, Burr J. Incidence of Iron Deficiency and Iron Deficient Anemia in Elite Runners and Triathletes. Clin J Sport Med. 2017 Sep;27(5):493-498. doi: 10.1097/JSM.0000000000000390. PMID: 27606953.
- Moretti D, Goede JS, Zeder C, et al. Oral iron supplements increasehepcidin and decrease iron absorption from daily or twice-daily dosesin iron-depleted young women. Blood. 2015;126:1981–1990.
- Pate RR, Miller BJ, Davis JM, et al. Iron status of female runners. Int JSport Nutr. 1993;3:222–231.
- Alaunyte I, Stojceska V, Plunkett A. Iron and the female athlete: a reviewof dietary treatment methods for improving iron status and exerciseperformance. J Int Soc Sports Nutr. 2015;12:38.
Could you be experiencing iron deficiency?
