Ferritin

What it is

Ferritin is a protein that stores iron. The amount in your blood is a good indication of how much iron your body has in reserve. It’s often tested as part of iron studies, alongside other iron markers.

Why it matters for training decisions

Iron is central to carrying oxygen in the blood and to energy production in muscle. A 2019 review led by Australian sports scientists noted that iron deficiency is common in athletes, especially women and endurance athletes. It’s reported in roughly 15–35% of female athlete groups and about 5–11% of male athlete groups. Exercise also raises hepcidin, the main hormone that regulates iron, which is thought to be one reason athletes’ iron levels can be harder to maintain.

Low iron stores can come before anaemia, so ferritin can be low while haemoglobin is still normal. Iron deficiency is also one of the conditions to rule out when an athlete seems overtrained.

Limits of the test

Ferritin rises with inflammation, infection and illness, so a normal or even high result doesn’t always rule out low iron stores. What counts as “low” for an athlete is debated, and laboratories use their own reference ranges.

Don’t start iron supplements based on a hunch or a single number. Too much iron can be harmful. Talk to your doctor, who can interpret ferritin with your other results and symptoms.

How P247 uses it

If you turn on AI features, you can scan a photo or PDF of your blood test. P247 reads the markers and their reference ranges, tracks them across tests and adds a plain-English summary for training. It isn’t a diagnosis.

This glossary is general information to help you understand your training data. It isn't medical advice, diagnosis or treatment. For injury, illness, medication, blood test results or any health concern, speak to a qualified health professional.

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