Iron balance, deficiency and supplementation in female athletes
What it found
In female athletes, iron deficiency anaemia reduces endurance performance, while the effects of low iron without anaemia are less clear.
Iron injections and oral supplements can raise iron stores in people.
What they found
Studies in people
Performance and iron deficiency
Iron deficiency anaemia clearly reduces endurance performance in athletes by limiting oxygen transport. Whether low iron without anaemia affects performance is less certain, with studies showing mixed results in people.
Heavy menstrual bleeding
Menstruating women lose about 1 mg per day of iron when bleeding. Heavy menstrual bleeding affects 1 in 3 athletes at all levels and raises the risk of low iron in people.
Altitude training effects
Moving to a simulated altitude of 3000m lowered stored iron and slowly raised total haemoglobin over 3 weeks in male and female endurance athletes. Returning to sea level improved iron status in people.
Testing iron levels
Blood tests for haemoglobin and ferritin are commonly used but can be misleading in athletes. Training changes blood volume and inflammation raises ferritin, so repeated tracking over time works better in people.
Supplements and injections
Oral iron doses of 40 to 400 mg per day for 6 to 24 weeks raised ferritin levels in athletes. Iron injections worked faster than pills at improving iron status in highly trained runners in people.
Studies in people and animals
Too much iron risks
There is no evidence that iron above normal levels improves performance beyond a placebo effect. In animal studies, too much iron raised markers of cell damage in the liver, kidney and blood.
What the authors conclude
- They advise regular blood screening and long-term tracking of iron and red blood cell measures for all female athletes.
- They recommend treating confirmed iron deficiency anaemia with medical guidance using either oral supplements or injections.
- They call for more controlled studies on dietary iron intake that account for female hormones, menstrual losses and training loads.
How it was done
Female athletes are at particular risk of low iron because of menstruation and the extra demands exercise places on the body. The authors wanted to gather existing research to help sports professionals identify and correct low iron in these athletes.
The authors gathered and examined published research on iron balance, testing methods and treatments in female athletes. They looked at factors such as diet, altitude training, menstruation and pregnancy. No new trials were run for this work.
What it can’t tell you
- Because this work gathers past research rather than running new trials, it cannot prove cause and effect on its own.
- Some findings rely on animal studies of iron overload, which may not match what happens in people.
- Studies following athletes over time can show links between iron and performance but cannot confirm that iron caused the change.
Who paid
- Authors work at
- St Mary's University, UK; Massachusetts General Hospital, USA; Boston Children's Hospital, USA
The paper
- Title
- Iron balance and iron supplementation for the female athlete: A practical approach
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Pedlar CR, Brugnara C, Bruinvels G, Burden R (2018). Iron balance and iron supplementation for the female athlete: A practical approach. European journal of sport science. doi:10.1080/17461391.2017.1416178Free full textPubMed 29280410DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error