Iron for Runners: Do You Need More?

Most runners do not need extra iron from a supplement, because a varied diet with plenty of iron-rich foods usually covers what the body needs. Regular running can nudge iron levels down, though, so eat iron-rich foods often and ask your GP for a blood test, rather than guessing, if you feel unusually tired or breathless. Here is how to eat for it, and when to get checked.

Why does iron matter for runners?

The NHS explains that iron is important in making red blood cells, which carry oxygen around the body. Every easy jog and hill rep relies on oxygen reaching your working muscles, and red blood cells are the delivery service. Iron also helps your muscles use that oxygen to produce energy.

When iron runs low for long enough, the body struggles to make enough healthy red blood cells. The NHS says a lack of iron can lead to iron deficiency anaemia, which is the most common type of anaemia. Some people also have low iron stores without being anaemic, which is why a blood test tells you more than how a run feels.

Do runners need more iron than other people?

Not on paper. The NHS does not give a separate daily figure for runners. But research reviews suggest people who do a lot of endurance training are more likely to run low on iron, for three main reasons:

• Small extra losses. Reviews describe a little more iron being lost through sweat, the gut and urine in people who train hard, and the impact of repeated foot strikes may break down some red blood cells.
• A short dip in absorption. After a hard endurance session, a hormone called hepcidin rises. Research suggests it peaks roughly 3 to 6 hours after exercise, and while it is high your gut absorbs less iron.
• Not eating enough. Training more without eating more means your iron intake drops too, and reviews point to low intake as a main reason endurance runners end up short.

It is worth paying a bit more attention to iron if you:

• run high mileage or are building up for a half marathon or marathon
• eat little or no meat or fish
• are cutting calories or often skip meals around training
• give blood regularly, since each donation removes some iron
• often take anti-inflammatory painkillers such as ibuprofen or aspirin. The NHS lists these among the causes of bleeding in the stomach and intestines, which is a common cause of iron deficiency anaemia.

How much iron do you need each day?

The NHS gives these daily amounts for adults:

• 8.7mg a day for men aged 19 and over
• 14.8mg a day for women aged 19 to 49
• 8.7mg a day for women aged 50 and over

The NHS also says you should be able to get all the iron you need from your daily diet. For most runners, the job is eating enough food overall, with regular sources of iron built into your meals. For the bigger picture on fuelling running and strength together, our guide on how to eat for hybrid training covers carbs, protein and meal timing.

Which foods are high in iron?

Iron in food comes in two forms. Haem iron comes from animal foods such as red meat, and your body absorbs it more easily. Non-haem iron comes from plant foods and fortified products. Your body absorbs less of it, but the right pairings help.

Good sources on the NHS lists include:

• red meat and other meat
• beans, such as red kidney beans, edamame beans and chickpeas, plus other pulses like peas and lentils
• nuts
• dried fruit, such as apricots, prunes and raisins
• fortified breakfast cereals, and bread with extra iron added
• dark-green leafy vegetables like watercress and curly kale
• soy bean flour

The NHS also points to Department of Health and Social Care advice to limit red and processed meat, so mix your sources. Here are easy meals that put iron and vitamin C on the same plate:

These are everyday examples, not a prescription. Fortified products vary, so check the label for iron content.

Should you stop drinking tea and coffee?

No, but timing helps. The NHS lists tea, coffee, milk and dairy, and foods with high levels of phytic acid, such as wholegrain cereals, as things that make it harder for your body to absorb iron when you have large amounts of them. Tea and coffee contain tannins, which get in the way of the iron in plant foods in particular.

You do not need to give up your morning coffee. Just have tea and coffee between meals rather than with your main iron-rich meal. If breakfast is your best iron meal, have your coffee mid-morning instead. Wholegrains are still a great choice for runners, so keep them in and keep your meals varied.

How do plant-based runners get enough iron?

Plenty of runners eat little or no meat and keep healthy iron levels. It just takes more planning, because plant iron is absorbed less easily. Three habits help:

• Put an iron source in most meals. Beans, lentils, chickpeas, tofu, edamame, nuts, seeds, dried fruit, fortified cereals and leafy greens all count.
• Add vitamin C to the same meal. UK dietitian guidance says eating plant iron with foods that contain vitamin C helps your body absorb it. Peppers, broccoli, oranges, kiwi, strawberries and tomatoes are easy wins.
• Keep tea and coffee away from those meals.

If you are new to plant-based eating and training hard, a registered dietitian can check your diet covers iron and the other nutrients you need.

What are the signs of low iron?

The NHS lists symptoms of iron deficiency anaemia that can include:

• tiredness and lack of energy
• shortness of breath
• noticeable heartbeats (heart palpitations)
• paler than usual skin
• headaches

For a runner, that might mean easy runs feeling harder than usual. The catch is that every one of those signs has other, more common causes, such as poor sleep, under-eating, a heavy training block, illness or stress. If you often feel wiped out after sessions, our guide on why you feel tired after working out covers the usual suspects.

There is a twist, too. The NHS describes haemochromatosis as an inherited condition where iron levels in the body slowly build up over many years, and feeling very tired all the time is one of its common symptoms. So tiredness on its own cannot tell you whether you have too little iron, too much, or neither. A blood test can. The NHS advice is simple: see a GP if you think you might have iron deficiency anaemia.

Should you take an iron supplement just in case?

It is best not to. The NHS says most people should be able to get all the iron they need by eating a varied and balanced diet, and warns that taking too much could be harmful. Here is what it says about supplements:

• Taking 17mg or less a day of iron supplements is unlikely to cause any harm. Only take more if a GP advises it.
• High doses (over 20mg) can cause side effects such as constipation, feeling sick, being sick and stomach pain.
• Very high doses can be fatal, particularly for children, so always keep iron supplements out of their reach.

Guessing also has a hidden cost: taking iron because you feel flat can delay finding the real reason.

How do you get your iron checked?

Book an appointment with your GP and explain how you have been feeling. The NHS says your GP will ask about your lifestyle and medical history, and will usually do a blood test called a full blood count to find out if the number of red blood cells you have is normal. Mention how much you run, any recent jump in training, what you usually eat and any regular medicines.

If your iron is low, the GP will look for the cause and recommend treatment, which may include iron tablets for several months and changes to your diet. Follow the GP's advice on how to take them, and do not change the dose on your own.

How does iron fit into a hybrid training week?

Iron is one small part of a bigger picture. If you run, lift and do HIIT in the same week, the basics carry most of the weight: eating enough, regular meals around sessions, good sleep and easy days that stay easy. For simple ideas on fuelling each session, see what to eat before and after running.

Edge plans running, strength, HIIT and mobility as one programme, so hard days, easy days and rest are planned together. Edge is free to use, and Edge Pro, from £19.99 a month with a 7-day free trial (you add a card to start), gives you a fully personalised plan ready within 24 hours and a real coach you can message anytime. If sessions keep feeling unusually hard, message your coach about your training, but checking your iron is a job for your GP.

This article is general guidance, not medical advice. If you are new to exercise, returning from injury, or managing a health condition, speak to your GP before starting, and see a physio for any niggle that does not settle.