CGHS Track and XC - Iron and Ferritin

Introduction

There is a lot of information below, but this topic can be a bit complex and it's often not as simple as eating a diet high in iron. After reading the background information please pay attention to the details in the section below about testing. Coaches in many programs recommend that every incoming freshman female get ferritin levels tested before they enter high school even if they aren't showing symptoms. It can take months for the deficiency to show up and by that time an entire season can be lost. An article specifically about high school girls and ferritin levels can be accessed HERE.

Iron, Ferritin, and Distance Running

Iron is one of the most important nutrients for distance runners because it helps your body make hemoglobin, the protein in red blood cells that carries oxygen from your lungs to your working muscles. When iron levels are too low, your muscles receive less oxygen, making running feel much harder than it should. It can feel like trying to pedal a bike with low tire pressure, lots of effort with poor results.

Ferritin is different from iron. Think of ferritin as your body's iron savings account. When daily iron intake isn't enough, your body withdraws from those savings. Eventually, if the savings account becomes too low, the body begins having difficulty making enough healthy red blood cells. While iron is the nutrient your body uses every day, ferritin is the stored reserve your body can draw from when it needs more. A runner may have normal iron levels today but low ferritin, meaning their iron "tank" is running low. If those iron stores continue to decrease, iron deficiency—and eventually anemia—can develop.

Why Distance Runners Are at Higher Risk

Distance runners use more iron than many other athletes for several reasons:

Running creates repeated impact on the feet, which can damage a small number of red blood cells with every step (foot-strike hemolysis).
Iron is lost through sweat.
Rapid growth during the teenage years increases iron needs.
Many athletes, especially girls, lose additional iron through menstruation.
High training volumes require more oxygen delivery to muscles, increasing the body's demand for iron.

Because of these factors, iron deficiency is one of the most common nutritional concerns among high school distance runners.

Signs That Iron or Ferritin May Be Low

Low iron or ferritin doesn't usually cause one bad workout—it tends to cause a gradual decline over several weeks or months. Common warning signs include:

Feeling unusually tired during or after runs
Needing much longer to recover between workouts
Declining race performances despite training consistently
Feeling out of breath at paces that used to feel comfortable
Difficulty finishing workouts
Frequent illness
Trouble concentrating at school
Feeling unusually cold
Pale skin

Why Ferritin Matters Even Before Anemia Develops

Many people think iron only becomes a problem once someone has anemia. In reality, low ferritin can begin affecting endurance performance before anemia develops.

When ferritin stores become depleted, the body has less iron available to make new red blood cells. Athletes may notice fatigue, slower recovery, and reduced endurance even though a standard blood test still shows a normal hemoglobin level. This is why sports medicine providers often check both hemoglobin and ferritin in endurance athletes who have symptoms.

Preventing Iron Deficiency

Most healthy runners can reduce their risk by:

Eating a balanced diet that includes iron-rich foods such as lean beef, chicken, turkey, fish, beans, lentils, spinach, fortified cereals, and tofu.
Pairing iron-rich foods with foods high in vitamin C (such as oranges, strawberries, bell peppers, or tomatoes), which helps the body absorb iron more effectively.
Avoiding drinking large amounts of milk, tea, or coffee with iron-rich meals because they can reduce iron absorption.
Talking with a healthcare provider if fatigue, declining performance, or other symptoms develop.
Never taking iron supplements unless recommended by a healthcare provider. Too much iron can be harmful, and supplementation should be based on blood work rather than guesswork.
Athletes with heavy training loads, a history of iron deficiency, vegetarian or vegan diets, or heavy menstrual periods should discuss iron screening with their healthcare provider.

Testing Ferritin Levels - Where to Go

Your primary care physician is a great place to start, but it might take time to get an appointment. Many primary care physicians are not as familiar in working with distance runners, so it often takes patients asking specifically for a ferritin test and not just an iron test. BE SPECIFIC and clear that you want ferritin numbers included with the test results. Interpath Laboratory in Springfield also offers quick and inexpensive testing, but you don't get the consultation with a doctor. This is a nice option for someone that has been taking iron supplements that just wants a quick test to see if supplementation has been working. See the graphic below for suggestions on how get the most accurate test results before going in to get tested.

The following is from a slide from a presentation by Trent Stellingwerff (PhD, FACSM, CEP, ChPC) from Women's Health Sports & Performance Institute and Canadian Sport Institute Pacific.

Testing Ferritin Levels - Results

The result part is where things can get a little tricky. Some doctors might say that bloodwork is fine if ferritin levels fall inside the range of 12 to 300ng/mL for women. I've had athletes told by a doctor that they are "fine" with a ferritin level of 12ng/mL yet they are suffering on nearly every run. The problem is that "normal" ferritin levels are established for the general population and not for people that are distance running and destroying red blood cells with every foot strike. More recently, we have had greater success with doctors recognizing that endurance athletes require much higher levels to be healthy than the average person. An article linked HERE describes what healthy ferritin levels should look like for runners. See the chart below for a breakdown of iron deficiency in runners. Based on the chart, a level below 30ng/mL is considered depleted. I encourage you to do your own research as well.

Ferritin Levels Low? Now What?

This isn't a quick fix, it can take weeks to improve. For endurance athletes an iron rich diet is often not adequate for raising low levels or maintaining healthy levels. However, any supplementation should be approved by a medical professional. Iron supplementation can be confusing because of all the options available from pills to liquids and many different sizes of doses. Certain supplements may work better for some than others and there can sometimes be some side effects like gastrointestinal distress. It may take some trial and error to find what works best for each person.

As a parent I'm always concerned about the impact that any supplement might have on my child. Both of my daughters have had low ferritin levels and we have tried several methods to improve those levels, some have worked and some haven't. I've also had many conversations with parents and athletes over the years about what has or has not worked for them. I'm happy to share what I've learned, but again, I'm not a doctor and the decision is ultimately up to the parents and athletes.

Final Notes

Fitness doesn't disappear overnight, but low iron can make it feel like it did. If a runner who has been training consistently suddenly feels unusually tired for several weeks, struggles to complete normal workouts, or sees a steady decline in performance, iron status is one of the first things that should be considered alongside adequate fueling, sleep, and overall recovery. Almost every female athlete in our program that has experienced these symptoms and has been tested has been well below 30 ng/mL with initial screening. In fact, we have had several athletes test below 5 ng/mL and appropriate iron supplementation provided astronomical improvement over time. Health and performance improved along with a decreased risk of injury. Even if an athlete is not experiencing these symptoms it can be beneficial to know the numbers as it's easier to be proactive than it is to be reactive once there is a problem. Please don't be afraid to ask if you have questions.

Parents should notify coaches if an athlete is being evaluated for iron deficiency or another medical condition so that training can be adjusted appropriately if needed.

Disclaimer

This page is intended for educational purposes only and is not a substitute for medical advice. Every athlete is different. If you have concerns about your athlete's iron status, persistent fatigue, declining performance, or overall health, consult your healthcare provider or a sports medicine physician. Never begin iron supplementation without medical guidance and appropriate blood testing.