Iron Deficiency in Runners: What You Need to Know and How to Fix It

For runners, performance depends not just on training, but on the body's ability to deliver oxygen efficiently to working muscles. One critical nutrient in that process is iron—a mineral that plays a central role in producing hemoglobin, the protein in red blood cells responsible for carrying oxygen throughout the body. When iron levels are low, oxygen transport is compromised, and the results can be frustrating: fatigue, shortness of breath, and a noticeable decline in endurance.

At Oregon Running Clinic, we often work with runners struggling with unexplained plateaus or persistent fatigue—issues that are sometimes traced back to low iron or ferritin levels. Understanding how iron deficiency impacts performance and knowing how to address it can be a game changer in your training and race results.

How Iron Deficiency Affects Runners

Iron deficiency can significantly reduce aerobic capacity and VO₂ max, limiting how efficiently your body uses oxygen. Even if your hemoglobin levels are within a normal range, low ferritin (your iron storage marker) can impair muscle oxygenation and delay recovery.

This condition doesn’t just sap your strength—it can cause chronic fatigue, high heart rate during exercise, and poor race-day performance. You might also experience frequent injuries or illnesses due to a weakened immune response.

Female runners, in particular, face additional challenges due to iron loss during menstruation.

Common iron losses for runners include:

  • Foot strike hemolysis (red blood cells breaking from the repetitive impact of running)

  • Sweating

  • GI bleeding, particularly during intense training

  • Poor dietary intake, especially in plant-based diets lacking in absorbable iron

Ways to Boost Iron Levels

The good news? Iron deficiency is treatable—and performance can bounce back quickly once levels are restored. Here are some proven strategies:

1. Iron-Rich Foods

Prioritize foods high in heme iron, the form most easily absorbed by the body:

  • Red meat (beef, lamb)

  • Poultry (dark meat chicken, turkey)

  • Liver and organ meats

Non-heme iron (from plant sources) is less absorbable but still beneficial, especially when eaten with vitamin C:

  • Spinach, lentils, beans, tofu, fortified cereals

  • Pair with citrus fruits, bell peppers, or tomatoes to enhance absorption

2. Iron Supplements

When diet isn’t enough, oral supplements can help. Ferrous sulfate or ferrous gluconate are commonly recommended forms. Take iron:

  • On an empty stomach or with vitamin C

  • Away from calcium, dairy, or coffee, which can block absorption

It is advised you work with a healthcare provider to monitor dosage and avoid side effects like constipation or nausea.

3. Iron Infusions

For severe deficiencies or those who can’t tolerate supplements, IV iron infusions offer fast, effective replenishment. These are often used for athletes with dangerously low ferritin levels or chronic fatigue not resolved by oral methods.

Train Smarter with Oregon Running Clinic

If you're a runner battling fatigue, poor recovery, or underperformance, it may be time to check your iron levels—and rethink your training strategy. At Oregon Running Clinic, we take a holistic approach to running performance, combining expert diagnostics, individualized training plans, and nutritional support to help you run your best.

Don’t let low iron hold you back. Schedule a consultation today and take the next step toward smarter, stronger running.

Charlotte Spangler