You’ve trained hard, followed the plan, eaten well — but your body still feels sluggish, your legs heavy, and your times slower. Before you blame your fitness, consider another possibility: runner’s anaemia caused by foot-strike haemolysis.
These might sound like medical jargon, but they’re surprisingly common — and treatable — issues among runners. Let’s break them down.
What is Runner’s Anaemia and Foor Strike Haemolysis?
Runner’s anaemia is a type of iron deficiency that happens when the body doesn’t have enough iron or healthy red blood cells to meet the demands of running. It’s especially common in long-distance runners, women, and athletes training at high intensity (Marathon Handbook, 2022; Sim et al., 2019).
One of the main causes is something called foot-strike haemolysis. This happens when the repeated impact of your feet hitting the ground damages red blood cells in the tiny vessels of your feet. Over time, this “internal wear and tear” reduces your red blood cell count — and with fewer red blood cells, your muscles get less oxygen (Gartner et al., 2024). That’s when you might start feeling unusually tired, heavy-legged, or short of breath, even if your training hasn’t changed.
According to Gartner et al. (2024), foot-strike haemolysis is a well-documented and often overlooked issue in endurance athletes. The effect is even greater when running on hard surfaces or wearing shoes with poor cushioning.
When red blood cells break down faster than your body can replace them — and your iron stores can’t keep up — it can lead to a drop in performance and slower recovery. This is what we call runner’s anaemia.
Why Red Blood Cells Matter for Running
Red blood cells (RBCs) are your body’s oxygen couriers. They contain haemoglobin, a protein that binds to oxygen in your lungs and delivers it to your muscles.
Fewer red blood cells = less oxygen delivered = lower performance and slower recovery (Hinton, 2014).
To make healthy red blood cells, your body also needs iron, vitamin B12, and folate — all nutrients that can be depleted through intense or frequent training (Latunde-Dada, 2013).
Signs You Might Be Affected
Even if your blood tests look “normal,” you might still be feeling the effects of low iron or haemolysis-related red blood cell destruction.
Common signs include:
• Heavy legs or unexplained fatigue
• Feeling short of breath during your usual runs
• Increased heart rate for the same effort
• Dizziness or brain fog
• Poor race or recovery performance
• Repeated illnesses or injuries
Research by Sim et al. (2019) shows that even mild iron deficiency — before anaemia develops — can impair endurance, cognitive function, mood, and overall performance.
Other Contributors to Runner’s Anaemia
While foot-strike haemolysis plays a key role, other factors can make anaemia worse:
• Menstruation in women (Deldicque & Francaux, 2015)
• Iron lost through sweat (Hinton, 2014)
• Low dietary iron intake, especially in vegetarian diets
How to Know What’s Going On: Test, Don’t Guess
If you’re feeling unusually tired, struggling through your runs, or constantly low on energy — it could be more than just training load. Low iron or nutrient imbalances might be the real culprit.
At Epicentre, we offer two powerful testing options to help you understand what’s going on in your body.
Focused Testing for Iron Deficiency
This package is perfect if you’re specifically concerned about fatigue, dizziness, or symptoms of low iron. It checks the key nutrients involved in making healthy red blood cells:
• Serum Iron: Measures how much iron is circulating in your blood right now.
• Transferrin: A protein that carries iron; levels increase when your iron stores are low.
• Ferritin: Your body’s long-term iron storage — often low before anaemia shows up on basic tests.
• Vitamin B12: Essential for red blood cell production and energy. Deficiency can lead to B12-deficiency anaemia.
• (Optional add-ons:)
o Folate (Serum or RBC): Needed for red blood cell creation and DNA synthesis.
o Full Blood Count (FBC): Gives a broad view of your blood cell health and helps detect anaemia or other conditions.
If you suspect iron-deficiency anaemia, this test is a smart first step — and no referral is needed.
For Athletes Who Want the Full Picture
If you want a more all-rounded view of your athletic health — not just iron, but hydration, muscle recovery, and bone strength — go for the Runner’s Panel. It includes everything from the anaemia package and much more:
• Iron Profile (Ferritin, Serum Iron)
• Vitamin B12
• Vitamin D – Supports bone health and immunity
• Calcium & Magnesium – Muscle and bone function
• Urea, Electrolytes & Creatinine – Hydration, kidney function, and muscle recovery
• Liver Function Tests (LFT) – Detects liver stress from intense training or supplement use
• Fasting Glucose – Energy and fuelling balance
• Lipogram (HDL & LDL Cholesterol) – Cardiovascular health for endurance performance
• Full Blood Count (FBC) – Red and white blood cells, haemoglobin, platelets
Optional extras include:
• Zinc: For immune support and recovery
• Folate (RBC): A deeper view of folate status
How Epicentre Can Help
At Epicentre, we specialise in athlete-friendly, functional lab reports — not just clinical ones. Our testing:
✅ Doesn’t require a doctor’s referral
✅ Is available at walk-in labs in Cape Town, Durban, and Johannesburg
✅ Gives you full insight into your iron, red blood cell, and recovery status
Take Control of Your Health and Your Stride
Foot-strike haemolysis and runner’s anaemia are real, but they’re manageable once detected. Testing gives you the power to adjust your diet, training, or recovery strategy with confidence.
🩸 Test smart. Train smart. Run strong.
References (APA 7th)
Burke, D. E., Johnson, J. V., Vukovich, M. D., & Kattelmann, K. K. (n.d.). Effects of lean beef supplementation on iron status, body composition and performance of collegiate distance runners. South Dakota State University. https://openprairie.sdstate.edu/cgi/viewcontent.cgi?article=6884&context=etd
Deldicque, L., & Francaux, M. (2015). Recommendations for healthy nutrition in female endurance runners: An update. Frontiers in Nutrition, 2, Article 17. https://doi.org/10.3389/fnut.2015.00017
Gartner, A., Dombrowski, N., Lowe, N., Behzadpour, V., & Zackula, R. (2024). Foot-strike hemolysis: A scoping review of long-distance runners. Kansas Journal of Medicine, 17(5), 119–124. https://doi.org/10.17161/kjm.vol17.22146
Hinton, P. S. (2014). Iron and the endurance athlete. Applied Physiology, Nutrition, and Metabolism, 39(9), 1012–1018.
Latunde-Dada, G. O. (2013). Iron metabolism in athletes—Achieving a gold standard. European Journal of Haematology, 90(1), 10–15. https://doi.org/10.1111/ejh.12026
Marathon Handbook. (2022, November 17). Runner’s anemia: Running and iron deficiency. https://marathonhandbook.com/runners-anemia/
Sim, M., Garvican-Lewis, L. A., Cox, G. R., Govus, A., McKay, A. K. A., Stellingwerff, T., & Peeling, P. (2019). Iron considerations for the athlete: A narrative review. European Journal of Applied Physiology, 119, 1463–1478. https://doi.org/10.1007/s00421-019-04157-y
Taheri Chadorneshin, H., & Nazari, S. (2020). The impact of rope jump exercise training on hemolytic anemia parameters in obese adolescent boys. Zahedan Journal of Research in Medical Sciences. https://doi.org/10.5812/zjrms.106947
