Iron Deficiency in Athletes: What You Need to Know
Athletes, particularly female endurance athletes, are more prone to iron deficiency for several reasons. Exercise impacts the body’s ability to absorb iron by increasing a hormone called hepcidin, which blocks iron absorption. Additionally, athletes lose iron through sweat and can experience “foot strike haemolysis,” where red blood cells burst from the shearing force of foot strikes.
The Importance of Ferritin Levels
There is evidence from placebo-controlled trials that people report feeling better and having improved energy if their ferritin levels are above 50ug/L. This is the target I aim for in my patients.
Personal Experience with Low Ferritin
I was shocked today when I received results showing my ferritin level was 10, which is quite low. Despite this, I feel fine and even achieved my personal best lap time at Centennial Park yesterday! However, after reviewing my other results and literature on athletic performance, I was reassured. My low ferritin is likely due to a dilution effect from increased plasma volume after altitude training. Supporting this, my other blood parameters are normal. My haemoglobin was 143g/L (115-170), the size of my red blood cells was normal (MCV 93), and my transferrin saturation (a carrier protein that transports iron) was normal at 23%.
Iron Infusions and Performance
Even if my low ferritin is a true result and I am iron deficient, an urgent infusion is unlikely to improve my performance. Studies have shown that giving non-anaemic iron-deficient patients iron infusions does not improve performance. This is where diet and oral supplements should be trialed, aiming to diagnose mild iron deficiency before it becomes anaemia.
Recommendations for Athletes
I recommend that athletes, especially those who are vegetarian or menstruating, have their iron levels checked 1-2 times per year. I encourage taking oral iron supplements on alternate days, as this is cheaper, easier on the gut, and provides similar net absorption to daily supplementation. It’s best to take iron in the morning when hepcidin levels are lower.
By understanding the factors that contribute to iron deficiency and taking proactive steps to manage it, athletes can maintain their performance and overall health.