Nutrition Hotline
Anemia in Runners
By Reed Mangels, PhD, RD
QUESTION: My doctor wants to test my blood to see if I'm anemic. I should add that I'm a 19-year-old female, have been vegan for five years, and eat a really healthy diet. I've been training for a marathon for the past nine months. The doctor mentioned something about runner's anemia. Is that a real condition or is it that my veganism is making her nervous? E.H., via email
ANSWER: It's probably smart for all female endurance athletes to get checked for iron deficiency. There are several considerations running through your doctor's mind. First of all, iron deficiency is one of the most common nutritional problems in women. About 10% of U.S. non-pregnant women have iron deficiency; 5% have iron deficiency anemia.1 Women lose some iron every month through menstruation. If your flow is heavy, you are at a higher risk for iron deficiency.
Secondly, runner's anemia is a condition that can occur in distance runners. Some iron is lost with heavy sweating, and there may be small amounts of blood lost from the intestinal tract.2 Distance runners may lose red blood cells (the part of the blood that contains iron) due to blood cell destruction. In other words, when a runner's feet strike the ground repeatedly, red blood cells in the feet are damaged.2
The magnitude of all of these losses is small, but with time, they can compromise performance if iron deficiency develops. Iron, as a part of hemoglobin in the blood, helps to carry oxygen through the body. If enough oxygen doesn't get to the exercising muscles, performance can suffer. You may feel short of breath on an uphill or feel dizzy or lightheaded or more tired than usual.
If you're a frequent blood donor, you may also be at higher risk for iron deficiency. Your body may not be able to completely compensate for the blood loss, especially with other stressors like menstrual blood loss and blood loss related to exercise.
Eating a really healthy diet is an important way of reducing your risk for iron deficiency. Vegan foods such as dried beans, soy products, dark green vegetables, and whole grains can provide generous amounts of iron. There are substances in plants, called phytates, that interfere with iron absorption. Their influence can be reduced by including vitamin C sources like citrus, berries, broccoli, and tomatoes with meals to enhance iron absorption. You can read more about iron and vegan diets on our website, vrg.org
REFERENCES:
1Gupta PM, Hamner HC, Suchdev PS, Flores-Ayala R, Mei Z. Iron status of toddlers, nonpregnant females, and pregnant females in the United States. Am J Clin Nutr. 2017;106(Suppl 6):1640S-1646S.
2 Larson-Meyer DE, Ruscigno M. Plant-Based Sports Nutrition. Champaign, IL: Human Kinetics; 2020.
