Iron deficiency is one of the more common medical conditions among runners. Especially women. Consider the fact that more than one out of every five American women between the ages of 13 and 50 suffers from iron deficiency. That rate is certainly higher among American women who run. (Among men, about one out of every 15 Americans are iron deficient.)

Compounding the problem is that about 15-20 percent of the American women who are iron deficient are also anemic. A person becomes anemic when the iron stores in her body are depleted, rather than just low. Once again, women runners are especially susceptible to developing some degree of anemia.

Why iron deficiency (and even worse, anemia) is a problem is for runners is because it hurts his or her ability to run. Even a slight deficiency will inhibit a runner’s energy level. There simply isn’t adequate energy to run or do other normal activities without feeling abnormally tired. In addition, an iron deficient runner will likely become irritable, moody and suffer from a general overall feeling of weakness.

Why this happens is because iron deficiency is most commonly characterized by a low hemoglobin level. Oxygen is transported in the blood by the red blood cells (the hemoglobin) which delivers the all important oxygen to your working muscles and other tissues. If the concentration of hemoglobin is reduced, your muscles get less oxygen and their capacity to work declines.

Even so, less than half of all the iron in the body is in the red blood cells. The rest is stored in the bone marrow, liver, spleen and other tissues and organs. Only when almost all these iron reserves are depleted is when someone is truly anemic.

Iron deficiency is the most common type of anemia among runners. Obviously, this is a serious problem for runners because they simply won’t have the energy to run or train much at all. Even if they can, the lower iron interferes with the muscles’ ability to clear lactic acid which makes the runner feel exhausted from what would normally be an easy run. Initially, runners will just assume they’re tired from a hard race, overtraining or workout. They may be anemic – their iron stores have been depleted – and not even know it.

Many medical researchers believe that runners – again, especially women – are at greater risk of having low iron or even being anemic than the greater population. The current research isn’t definitive that this is true, but runners generally are at a higher risk of depleting their ferritin – which is where the iron is stored in your bone marrow, spleen and other organs – than sedentary people. A low ferritin level is indicative of depleted iron reserves and there’s a distinct possibility that this could lead to anemia.

Why runners are at such a higher risk with this is because the causes of iron deficiency, anemia and low ferritin can be related to running. In addition to a poor, iron-deficient diet, some of the other causes are losses of small amounts of iron through sweat. Another way iron is lost is when there’s blood loss in the urine because the bladder gets bruised by the sloshing around of its contents during running. Another cause of iron loss is through gastrointestinal distress caused by taking too much aspirin or non-steroidal anti-inflammatories –¬†something runners are notorious for doing.

Runners also tend to absorb less iron in their diets because foods passes so quickly through their digestive tract. In addition, high-mileage runners tend to destroy the red blood cells in their feet because of the repetitive pounding of running.

With women runners, the greatest iron loss is related to menstrual losses. Yet another cause of iron deficiency among women is inadequate dietary intake of iron, especially among vegetarians who simply don’t get enough iron.

Fortunately, treating and preventing iron deficiency is remarkably easy. If you have been positively tested for iron deficiency, merely taking daily iron supplements can correct this quickly and safely. Eating iron-rich foods will certainly help as well.

But iron dosing isn’t a good idea as a preventive measure for runners. Too much iron can cause serious constipation and it can interfere with the body’s ability to utilize zinc, another important mineral.

Without a doubt, the best way to control and prevent iron deficiency is to eat a properly balanced, iron-rich diet. The best form of dietary iron is found in fruits, veggies, whole grain products and nuts. It’s also found in many animal products, including red meat or dark poultry.

Even though this type of dietary iron is abundant in most diets, it isn’t absorbed very well by the body. Even worse, some types of grains and vegetables, tea, coffee and red wine can decrease its absorption rate by 40 to 80 percent.

On the other hand, some foods can enhance the absorption of iron. Vitamin C is one of the best (that’s why a glass of OJ every morning is a good idea for boosting your iron). Other foods that help are meat, fish and poultry. Some specific foods that are rich in iron include liver, oysters, beef, pork, tune and chicken. Less meaty choices include wheat germ, whole wheat bread, prunes, cooked lentils, tofu and broccoli.

Iron deficiency and anemia are serious problems for runners in general and women runners in particular. Clearly, the best way to prevent this condition by eating a healthy diet rich in iron. If you’re a vegetarian or restrict the amount of meat you eat, you may be at risk.

But by paying greater attention to the foods you eat and making certain you eat iron-rich foods (and possibly, taking iron supplement), you can avoid becoming iron deficient.