Have you been training more and struggling to complete your workouts due to feeling more fatigued or short of breath? If yes, you should have your iron levels checked. Endurance athletes are at higher risk for having an iron deficiency, which can impact your sports performance and health. It's not recommend to start supplementing with iron unless you are truly deficient confirmed through blood work prescribed by your physician.
How does endurance exercise impact iron levels? Iron has many roles to support your immune system, energy production, and most importantly to deliver oxygen to your working muscles. Iron is a major component of hemoglobin, the transport agent for oxygen and carbon dioxide in the blood. The act of running itself causes muscle damage and hemolysis (breakdown of red blood cells-RBC), as well as increasing iron losses through sweat and GI bleeding. Endurance exercise also increases blood volume and RBC production. However, the increase in plasma volume due to exercise is greater than the increase in RBC mass, resulting in a slightly lower hemoglobin level in endurance athletes than in non-athletes.
Who's at risk for an iron deficiency? Low iron or anemia can also be found more often the following groups of athletes: 🏃♀️ Female athletes due to menstrual loss, especially in combination with an inadequate intake of iron in the diet. 🥕 Vegetarians and/or vegans are at greater risk of anemia since they do not eat meat which contains heme iron. Heme iron from animals is better absorbed by the body than iron from plant based foods. ⬇️ Athletes with low energy intake are also at risk for having low iron because iron intake is insufficient to support the energy demands from exercise. ⬆️. Adolescent athletes are at higher risk due to increased demands with growth. What should you test? If you are at risk for having low iron or are struggling with fatigue not related to poor sleep, you should get a simple blood test to determine if you have low iron or iron deficiency anemia (IDA). Iron is stored as ferritin. Ferritin levels have a great impact on the iron absorbed from the diet. An athlete can have low ferritin but normal RBC and hemoglobin levels, but still have symptoms of fatigue. They may not be anemic but can benefit from increasing the iron in the diet and may need supplementation as well (prescribed by your physician) to reach optimal levels. True iron deficiency anemia (IDA) means you may have a deficiency of RBC, hemoglobin and ferritin levels. There are 3 stages of iron deficiency: 🩸 Iron-deficiency anemia (IDA)-most severe state, will impact sports performance due to lower hemoglobin levels. -ferritin (less than 12 ug/L) -hemoglobin (less than 11.5 mg/dL) - transferrin saturation (less than 16%) 🩸 Iron-deficiency non-anemia (IDNA): precursors to IDA, sports performance may be impacted. -ferritin (less than 20 ug/L) -hemoglobin (greater than 11.5 mg/dL) -transferrin saturation (less than 16%) 🩸 Iron-deficiency: low iron but not anemia: may or may not impact sports performance. -ferritin (less than 35 ug/L) -hemoglobin (greater than 11.5 mg/dL) -transferrin saturation (greater than 16%) It's important to get a blood test to best assess your iron status in the morning, but make sure you are well-hydrated and rested from exercise at least 12 hours before the test. Muscle damage can increase inflammation which can impact the results of your iron level. You should also show no signs of illness or infection before getting blood work. Overall, if you are found to be deficient, you should plan on getting testing at least twice a year to assess your iron status after proper diet and supplementation treatments have been in place.