Two women in active-wear running up steps outside

Why you need iron in endurance sports

Training for an event and feeling more tired than usual? Find out whether low iron levels could be the cause.

If you’re into long-distance running, cycling, tough gym workouts – or any other sport that demands a lot from your muscles – your body is likely to need a good supply of iron.

But this micronutrient doesn’t just have important health benefits for your body – it can help your sports performance, too.1

What does iron do in the body?

Iron is essential for making red blood cells including haemoglobin, a protein in red blood cells.

Its job is to transport oxygen from the lungs around the body, helping to ensure a steady supply of oxygen to your heart and muscles.2

How does iron support exercise?

Iron ensures your heart beats at a steady rate while you exercise.3 This essential nutrient also helps turn the food you eat into energy to power your muscles. Our muscle cells rely on oxygen – carried by iron-rich haemoglobin – to convert carbohydrates into energy.4

Why are you at risk of iron deficiency in endurance sports?

One reason is simply that you need more iron to meet your body’s needs when you exercise for a long time. Another is that you lose small amounts of iron when you sweat.5,6 The action of running, particularly the repeated striking of your heel on the ground, is also thought to destroy red blood cells, causing iron loss.7

Women and iron

Iron loss from exercise is compounded by the monthly iron loss during your period, so women athletes are more likely to suffer from iron deficiency than men.8 A 2015 review, published in the Journal of the International Society of Sports Nutrition, found that women runners were more likely to have low iron levels than women who didn’t do any exercise.9

Handpicked Content: Five surprising reasons you’re not getting enough iron

Symptoms of exercise-induced iron deficiency

Worried that you could have low iron levels? Look out for these symptoms:10
  • shortness of breath when you exercise
  • fatigue
  • lack of energy
  • pale skin
  • nausea
  • frequent infections

Handpicked content: How can ginger help with nausea?

Good food sources of iron

It’s a good idea to include plenty of iron in your diet. The following foods all contain excellent plant sources of iron:11
  • dark green, leafy veg
  • dried fruits, particularly figs, apricots and dates
  • pulses, like butter beans, chickpeas and kidney beans
  • sesame seeds
  • sunflower seeds
  • nuts
To help your body absorb iron from plant sources, accompany your meal with food or drink rich in vitamin C, like a glass of orange juice.12
Advice is for information only and should not replace medical care. Please check with your GP before trying any remedies.

Sources

1. Hinton PS. Iron and the endurance athlete. Available from: https://www.ncbi.nlm.nih.gov/pubmed/25017111
2. British Dietetic Association. Food fact sheet: iron. Available from: https://www.bda.uk.com/foodfacts/iron_food_fact_sheet.pdf
3. Healthline. How iron deficiency affects athletes. Available from: https://www.healthline.com/health/increasing-iron-intake-improve-athletic-performance#athletic-performance
4. Gupta CP. Role of Iron (Fe) in Body. Available from: https://pdfs.semanticscholar.org/f242/cd23c65c0b77dd17859208792ea96ae2917d.pdf
5. As Source 1
6. Ottomano C and Franchini M. Sports anaemia: facts or fiction? Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3417720/
7. As Source 7
8. Alaunyte I, Stojceska V and Plunkett A. Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4596414/ - CR34
9. As Source 9
10. Brumitt J, McIntosh L and Rutt R. Comprehensive Sports Medicine Treatment of an Athlete Who Runs Cross-Country and is Iron Deficient. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953317/
11. As Source 3
12. Hallberg L, Brune M, Rossander-Hulthen L. Is there a physiological role in iron absorption? Available from: https://www.ncbi.nlm.nih.gov/pubmed/3304065

Iron