This week I had originally planned to post the next installment on our summer conditioning, looking at training groups, volume, and paces. However, I decided to put that on hold momentarily to discuss something . Iron deficiency is a topic that in the eyes of many elite coaches is highly important and lowly discussed. Before going any further, I did want to say from the outset that I am not a medical professional, so please take all of the information below in consultation with a physician. That being said, I hope this post can prove helpful in addressing an issue I do think is probably affecting a number of our runners. Monitoring iron levels can help our runners remain healthy and reach their goals. The main points can be summarized as follows:
If you have any questions feel free to reach out! ![]() Jonathan Dalby ran high school cross country with Matt Tegenkamp, arguably the most successful male runner from Missouri. Currently Dalby is the coach at Mountain Vista in Colorado, where his boys have finished as high as third and his girls have won a title at Nike Nationals. One of the things he preaches to both his runners and anyone else willing to listen is the importance of ferritin testing. What Is Ferritin?I'm going to try not to turn this into biology class. I'm not the one for that job, so let's keep things simple. 90-95% of the energy used in a 5k comes from the aerobic system, but this process requires oxygen, and quite a bit of it. Obviously that oxygen enters your bloodstream through your lungs when you breathe, but then it has to get transported throughout your body to the cells in all of your muscles. How does that happen? Red blood cells. But on a smaller scale. the oxygen bonds to the protein hemoglobin within those cells. The central structural component of hemoglobin is iron. So a distance runner needs lots of iron because they need lots of hemoglobin in lots of red blood cells transporting lots of oxygen to produce lots of energy over lots of time. That's lots of lots. The lifespan of a red blood cell is roughly four months, so the body is constantly producing new ones. But to make matters worse, endurance running tends to expedite the destruction of red blood cells, requiring the body to make even more. All of that production takes iron. So what happens when someone's body doesn't have enough iron? Besides a number of other issues, it struggles to produce the required energy levels, especially during periods of high demand (like maybe a cross country race). That's going to put runners in jeopardy of not only decreased performance in training and competition, but ultimately a host of other health risks. That's why it's immensely important for runners to maintain adequate iron levels. But how does someone know that those are up to par? A blood test can be done for hemoglobin (the Red Cross does a bunch of them at blood drives). However, the problem is that such a test only detects the iron in active use. It doesn't measure the iron the body has on reserve. Someone could have sufficient hemoglobin levels at the moment of testing, but it their reserves are low and they begin exercise that destroys red blood cells, the hemoglobin levels will drop. Furthermore, iron plays a role in a number of other parts of the aerobic process. Even having enough iron for hemoglobin might not leave enough for these other needs. To determine the amount of iron on reserve in someone's body, one needs to look to ferritin, a different protein used to store (and in some cases transport) iron. Low ferritin levels indicate iron deficiency. Ultimately this can lead to low hemoglobin and thus a low red blood cell count, a condition many are familiar with as anemia. ![]() During John Davis's tenure as an assistant coach at Edina High School, their boys made Nike Nationals four years in a row. Since then he's completed his PhD in biomechanics and become one of the leading nerds in the sport. He's a favorite source on the science of running, and his articles have greatly helped me understand the role of ferritin. Is Iron Deficiency |
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June 2025
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