Updated: Jun 7

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 9 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.

My hope is to raise awareness on this problematic yet treatable condition, because if left undiagnosed, it can have harmful and lasting ramifications. 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.


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).


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 the oxygen from hemoglobin so that muscles can function optimally. (5). Iron also plays an important role in metabolism, respiratory and immune function. (3).


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).


Too much iron or too little iron can cause serious health issues. (8). Our body can lose iron through gastrointestinal blood loss, hemolysis, menstruation, sweat loss and intense exercise. (9).

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 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 are 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 so as 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 is a hormone that acts as the central regulator in 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 there body will probably not be getting enough iron.


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 off 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 is an easy way to identify if an individual might be in a low iron state or even might 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 its 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).