I am not a medical doctor or dietician. I am coming at this from a coach's perspective having coached female and male athletes for the last nine years. I understand now how ignorant I was about this subject when I first started coaching and how if I knew then what I know now, I would have been able to help many more athletes. I am writing about a widespread problem that affects mainly female athletes- iron deficiency anemia.
I hope to raise awareness of this problematic yet treatable condition because it can have harmful and lasting ramifications if left undiagnosed. It is a conversation that goes hand in hand with talking to our female athletes about their menstrual cycles, another important topic I wrote about earlier this year, called Removing the Taboo.
OVERTRAINED OR IRON-DEPLETED?
Imagine that your training is going well until it is not. As an endurance athlete, you have listened to your coach and others about eating well, being healthy, and following the training program. Your diet has not changed but somehow your performance is constantly degrading when it should be getting better. Many coaches unknowingly will attribute the athlete's performance to just a "bad performance" or worse, a bad attitude.
Some coaches, (I was probably one of them at one point) are just not aware of the subtle signs. Some of these subtle signs include symptoms such as frequent infections, shortness of breath during exercise, respiratory illness, fatigue, weakness, pale appearance, lack of energy, depression, irritability, and unexplained poor performance are typical. (12).
Many athletes will become frustrated, confused, and begin to lack motivation. Others will chalk it up to overtraining, or blame themselves for undertraining and being lazy. While some of these issues may be true, the real culprit for many endurance athletes' chronic degradation in their performance may be due to iron depletion. (18).
WHAT IS IRON?
Iron is a mineral that is essential to endurance athletes due to its role in blood production. (2). Iron is important in maximizing athletic performance by getting oxygen to the body. (3). 70 percent of iron in the body is found in the red blood cells via hemoglobin and muscle cells called myoglobin. (4) Hemoglobin transfers oxygen in the blood from the lungs to tissues. (4). Myoglobin extracts oxygen from hemoglobin so that muscles can function optimally. (5). Iron also plays an important role in metabolism, respiratory and immune function. (3).
WHY IS IRON IMPORTANT?
Checking iron can be a way to evaluate if an athlete has a nutritional deficiency. One nutritional deficiency can shed light on other possible underlying nutritional deficiencies.
For example, Relative Energy Deficiency in Sport (RED-S) is one issue that can be closely tied with iron deficiency because it occurs when caloric intake is insufficient to meet the demands of calories burned through exercise, leaving the body in a constant energy deficit. (19). If calories are not being met then there is a high probability that the athlete also has low iron intake, poor absorption, and suppressed sex hormones. (12).
IRON INTAKE V. IRON LOSS
Our body takes in iron through our diet. Consumption of iron is essential for athletes wishing to achieve optimal athletic performance. (1). Iron from food comes in two forms: heme and non-heme. Heme is only found in the meat while non-heme is found in plants as well as a bit in meats and fortified foods. (11). It's important to know the difference because your body absorbs heme iron better than non-heme iron. (11).
Just because an individual is consuming iron does not mean the individual is absorbing the iron. There is a myriad of factors that can inhibit or increase your iron absorption. Eating and timing play an important role in how effective your body is at absorbing iron. Food and drinks containing caffeine and calcium may inhibit iron absorption. (16).
So if you are a coffee, tea, or milk drinker, you may want to time when you consume those beverages to not inhibit your iron absorption from other sources. So while fortified foods, such as cereal contain a good amount of iron, the calcium from your whole or almond milk might be blocking that iron from being absorbed.
On the other hand, Vitamin C has been shown to enhance iron absorption. (17). Drinking some orange juice or another citrus drink with your meal might help that iron absorption.
As implied in the name, iron deficiency occurs in an individual when the body does not have enough iron. A lack of iron in the blood means lack of oxygen to the muscles which equals a bad outcome for any endurance athlete.
Iron deficiency is one of the most common nutritional deficiencies when it comes to endurance athletes, especially female endurance athletes. (10). The numbers are quite staggering. One study identified 82% of female athletes as iron deficient. (21). Other studies show that 15-35% of female endurance athletes may be iron deficient while 5-11% of male endurance athletes are iron deficient. (20). Although a much higher percentage in females, this shows that male athletes can become deficient as well.
Think about trying to run a 5k while breathing through a straw. This is what it feels like for many athletes when their iron stores have become depleted.
HEPCIDIN "THE IRON BLOCKER"
Hepcidin is a hormone that acts as the central regulator of iron absorption. Hepcidin releases during intense exercise. (13). During the 3-6 hour window after intense exercise, hepcidin levels are elevated so athletes eating within that time frame will reduce the percentage of iron absorbed. (14).
Hepcidin levels are often overlooked. An athlete can be doing everything prescribed to them by health professionals but if the timing of their iron intake is during elevated hepcidin levels their body will probably not be getting enough iron.
WHAT IS FERRITIN?
Many people don't understand the difference between Ferritin and Iron and their function in the body. Ferritin is like a bank account for iron. One may start with a decent amount of money but if one only withdrawals money without ever depositing anything, pretty soon the account will be low or you will get the dreaded insufficient funds notification.
Ferritin is a biomarker of the total iron stores in your body. Ferritin stores iron in the bone marrow, liver, and other organs and releases iron as needed (3). Ferritin acts as a natural buffer against iron deficiency and iron overload. (6).
Checking our ferritin levels are an easy way to identify if an individual might be in a low iron state or even be at risk for iron overdose. If the ferritin test identifies that the individual is at risk of iron deficiency, further tests may be needed. (7)
Ferritin tests are the most commonly used test to check for iron deficiency due to their efficiency and relative cost compared to other tests. However, athletes should only get ferritin tested when they are rested and healthy. Ferritin levels (add link to ferritin levels) can spike for 2-3 days after intensive exercise. (15).
WHAT ARE LOW FERRITIN LEVELS?
There is a wide range for what falls within what is considered "normal ferritin levels," which range from 12 to 300 nanograms per milliliter (ng/mL). (20). There is no consensus for what is considered high, normal, or low ferritin levels. That is a process that requires input from the individual, family, and health professional on what is the best way to attack the problem.
STAGES OF IRON DEFICIENCY
There are three stages of iron deficiency. (20). In the first stage, there is a decrease in ferritin levels but hemoglobin remains the same. (20). During the second stage, iron stores are decreased. (20). In the last stage, the individual becomes anemic. (20).
Many sports physicians recommend getting a complete blood count with athletes who are suspected of iron deficiency, whether or not anemia is present. (20).
The treatment for iron deficiency will depend on what caused the deficiency and the severity of the deficiency. Treatment options typically include oral and intravenous therapy. The most common treatment for moderate to severe iron deficiency anemia (assuming it's just an iron intake issue) is a daily dosage of iron supplements which can be in liquid or pill form.
It may take a few months or even as long as a year to replenish your iron reserves, but luckily, one can start to feel the effects sometimes as early as a week or so after treatment begins. Be sure to have your blood work rechecked periodically to make sure the treatment is working.
Iron supplements may be tough to tolerate with some due to their associated side effects. No individual's diet is perfect but if you are an endurance athlete you need to make a conscious effort that you are consuming the required iron in your diet.
WHEN TO SCREEN AND WHO TO SCREEN?
I believe that all endurance athletes, even if healthy, should be screened at least once a year. Multiple times a year if you have multiple seasons that require an intensive workload. Athletes get a physical yearly to make sure that everything is going well within the body, so why would you not get tested for something that could affect your performances and have long-standing implications on your health?
Individuals who should get tested include the following:
● Females with heavy menstrual bleeding are at risk due to iron being lost due to bleeding.
● Vegetarians are at risk because they may not be consuming enough dietary iron.
● Anyone with a history of iron deficiency.
● Anyone suffering from the symptoms above without an explanation.
As coaches, parents, and other athletes we have to monitor these issues. We need to treat an athlete as being uncharacteristically fatigued, a poor performance when training indicates otherwise, stagnation in training, and other symptoms the same way you treat a check engine light on a car. While you can still drive your car while the check engine light is on, it would be negligible to ignore that there is or could be an underlying issue. It is our responsibility and duty as coaches and parents to protect our athletes. They trust us with their bodies and their health. The onus is on us, as a community, to do better!
The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Website.
8. Yokoi, Katsuhiko, and Aki Konomi. "Iron deficiency without anemia is a potential cause of fatigue: meta-analyses of randomized controlled trials and cross-sectional studies." The British journal of nutrition vol. 117,10 (2017): 1422-1431. doi:10.1017/S0007114517001349
15. Zügel, Martina et al. "Increased Hepcidin Levels During a Period of High Training Load Do Not Alter Iron Status in Male Elite Junior Rowers." Frontiers in physiology vol. 10 1577. 21 Jan. 2020, doi:10.3389/fphys.2019.01577
19. Loucks, A B, and E M Heath. "Induction of low-T3 syndrome in exercising women occurs at a threshold of energy availability." The American journal of physiology vol. 266,3 Pt 2 (1994): R817-23. doi:10.1152/ajpregu.1994.266.3.R817