Verlaag Ferritine Preventie en Herstel

Low Ferritin: The Hidden Reason You’re Exhausted on the Bike

Cycling fatigue has gotten complicated with all the training metrics and recovery protocols flying around. As someone who couldn’t figure out why my power numbers were dropping despite consistent training and good sleep, I learned everything there is to know about ferritin after a blood test showed mine was in the tank.

Fixed that, and everything came back.

What Ferritin Actually Is

Probably should have led with this section, honestly. Ferritin is the protein that stores iron in your body. When your cells need iron – especially for making hemoglobin in red blood cells – ferritin releases it. Low ferritin means your iron reserves are depleted, even if your hemoglobin looks normal.

This is why athletes can feel terrible before they’re technically anemic. Your ferritin can be low enough to impact performance while standard blood counts still show “normal” ranges.

Why Cyclists Are Vulnerable

Endurance exercise increases iron demand. Red blood cell production goes up with training. You also lose iron through sweat and, weirdly, through foot strike hemolysis – the slight destruction of red blood cells from repetitive impact.

Female cyclists have extra risk due to menstruation. Vegetarian and vegan athletes face challenges because plant-based iron absorbs less efficiently than iron from meat.

Put it together and active cyclists, especially women and plant-based eaters, frequently end up low in ferritin without realizing it.

Symptoms to Watch For

Fatigue that doesn’t match your training. Performance declining despite consistent work. Recovery taking longer than usual. Feeling flat on climbs that used to feel manageable.

Other signs: pale skin, cold hands and feet, shortness of breath, dizziness, unusual cravings, brittle nails, hair loss. If several of these overlap with unexplained performance drops, get tested.

The Testing

Ask your doctor for a ferritin test specifically, not just a standard CBC. Ferritin levels below 30 ng/mL often cause symptoms in athletes, even though labs might call 12-15 ng/mL “normal.” Normal for a sedentary person isn’t normal for someone training regularly.

Ideally you want ferritin above 50 ng/mL for athletic performance. Some sports doctors aim for 70-100 ng/mL for serious endurance athletes.

Dietary Fixes

Red meat is the most efficient source of heme iron (the kind your body absorbs best). If you eat meat, including it a few times per week helps maintain iron stores.

Plant sources like spinach, lentils, beans, and fortified cereals contain non-heme iron. Pair these with vitamin C (citrus, bell peppers, tomatoes) to boost absorption. A squeeze of lemon on your spinach salad isn’t just for flavor.

Avoid coffee and tea around iron-rich meals – they inhibit absorption. Same with calcium supplements.

When Supplements Make Sense

If your ferritin is significantly low, diet alone might not be enough to rebuild stores. Iron supplements can help but should be guided by a doctor – too much iron is also problematic.

Iron supplements can cause stomach issues. Taking them every other day might be as effective as daily and easier on your gut.

Severely depleted stores sometimes require IV iron therapy for faster recovery. This is medical territory, not self-treatment.

Prevention

Get tested periodically if you’re training hard, especially before big training blocks or events. Catching declining ferritin early is easier than rebuilding from depletion.

Pay attention to your diet year-round, not just during race season. Include iron-rich foods consistently. Don’t wait until you’re exhausted to think about nutrition.

My Experience

That’s what makes understanding ferritin endearing to us cyclists who’ve figured it out the hard way. My ferritin was 18 ng/mL when I finally got tested. Technically normal by lab standards. But bumping it to 65 ng/mL over a few months transformed my riding. Same training, way better results.

If unexplained fatigue is killing your cycling, get the test. It’s a simple blood draw that might explain everything.