Hemoglobin levels for runners

Hemoglobin is a protein in the red blood cell that help transport oxygen. Many athletes, especially runners and other endurance athletes, are concerned about their iron levels. This is because iron is a crucial component of hemoglobin. Anemia occurs when hemoglobin levels decrease below the normal range, with the most common cause being an iron deficiency. For a more detailed description of iron deficiency in endurance athletes, read our blog post here.

Endurance training increases the production of red blood cells and hemoglobin and increases plasma levels (the fluid that transports cells in the blood). (1,4) Often, the plasma levels increase more than hemoglobin production in runners and endurance athletes, and hemoglobin concentration may temporarily decrease.(2,5) Alternatively, dehydration and sweat from exercise can show up as a temporary rise in hemoglobin. (3) Variation in hemoglobin can occur due to many factors, it is important to interpret hemoglobin values alongside other biomarkers such as red blood cells, hematocrit, iron, ferritin, and other micronutrients essential in red blood cell production.