By Ian Nurse, DC

I love hills. I always have. I’ve never felt comfortable on a track trying to keep pace with my teammates but give me a hilly course or a few Summit Ave. repeats and I feel like I can hold my own. That’s why in the winter of 2012 I knew something was wrong when those hills I used to devour became my biggest fear and challenge. Over the span of a few months the slightest of inclines would seem like a mountain, and I was routinely losing my breath on hills that I used to bound up.

“I must be getting sick,” I reasoned to myself. However, I never got sick, nary a cough, sniffle, or fever. Despite the lack of symptoms, I felt chronically fatigued. It became an effort to get out of bed let alone run a few easy miles. Finally, I gave up on the impending sickness theory and went to see my doctor and have some blood work done. The result of which would lead me to an important understanding of a condition that according to recent studies affects over 50% of runners: iron deficiency anemia.

Anemia literally means a deficiency of red blood cells. However, there are many different types of anemia that can affect us: pernicious, aplastic, and sickle cell to name a few. As runners, we are most susceptible to iron deficiency anemia. Why is that important to runners? Well, as I’m sure most of you already know, red blood cells contain an iron-containing protein called hemoglobin that is responsible for carrying oxygen to our muscles. Less hemoglobin means less of that vital oxygen that we need to carry us up and over each and every hill.

So why are runners more susceptible to iron deficiency anemia? There are actually a few different reasons. First of all, the action of running literally breaks red blood cells with every foot strike. Termed “foot strike hemolysis,” red blood cells are damaged as the foot hits the ground and, thus, after thousands of steps, hemoglobin can be dramatically reduced. A second reason is that iron is lost in small amounts through sweating. While the numbers aren’t enormous for each run, when added up over the course of a long, hot summer, the loss becomes significant. Lastly, as runners we are often overly health conscious and, therefore, tend to shy away from consuming the best source of absorbable iron: red meat. While there are other sources of iron (including dark green leafy vegetables, legumes, egg yolk, and oysters), the far and away leader in terms of most readily absorbed comes in the form of heme iron which is derived from animal proteins like ground beef.

Unfortunately, the detection of iron deficiency anemia is a little more complicated than a simple blood test. Most doctors screen for anemia by drawing blood and performing a complete blood count (CBC) in which the red blood cells, hemoglobin, and hematocrit are measured. With iron-deficiency anemia, one’s hemoglobin and hematocrit will be on the low side (termed hypochromic/microcytic) but may not fall outside of the established levels. Thus, one’s doctor may not even diagnosis anemia in the first place and, further, won’t have a direct measure of one’s iron levels. For this reason, it is imperative that you ask your doctor for BOTH a CBC and an iron panel. The iron panel will provide the most important number for runners: the total stored iron, also known as ferritin. While there is some debate, most agree that ferritin levels below 40 ng/ ml for men and 30 ng/ml for women are significant enough to affect running performance.

While it can take years to deplete the body of iron, unfortunately, it also takes time to restore what has been lost. Thankfully, with the proper diagnosis and the help of supplementation and proper nutrition it usually only takes 6 months to replenish one’s iron stores (in other words, to feel back to normal bounding up those hills). Deficient runners should include 60 mg of iron in the form of ferrous sulfate via a liquid or pill supplement into their daily diet while trying to restore and just 30 mg while trying to maintain normal levels. However, one must be careful to avoid calcium, coffee, and tannins from tea and wine for the hour before and after as they hinder iron absorption. To further aid absorption, iron should be taken with vitamin C and a vitamin B complex. I try to take mine first thing in the morning on an empty stomach. It’s also important to have your ferritin levels re-checked after 3 months. Failure to absorb iron could be an indicator of a more significant digestive issue such as Celiac disease, while excessive levels of iron can become toxic.

While it was a long road back, I’m happy to say that I love hills again. Actually, with my iron levels back to where they should be, I love them even more now!

Ian Nurse is The Level’s resident doctor. He ran 2:25 at Boston this year. This article originally appeared in the Sep/Oct 2013 issue of Level Renner. Get your free subscription today (box in upper right portion of screen). Feature image courtesy of Krissy Kozlosky.