How Much Iron Does A Runner Need?

Most of us have heard of iron deficiency or low iron levels, but don’t know what it is or how it affects the body. Unfortunately, around 55% of runners have iron deficiency, many of whom don’t even know it.

Having low iron levels impacts your running performance and overall health. Female runners are at an increased risk of struggling with low iron due to menstruation. But that doesn’t mean men are off the hook.

Most runners prioritize their macronutrients, like protein and carbs, but micronutrients (like iron and calcium) are just as important. And when you consider that some people don’t metabolize some nutrients as well as others, this creates a big concern.

The first step is knowing how much iron you need as a runner and how to get that amount of iron into your body. Below, we’ll look at iron consumption requirements for runners — and how you can keep your iron levels where they need to be for optimal health and well-being.

Why Do Runners Need Iron?

How much iron do runners need?

Let’s look at iron as your oxygen tank. Iron helps you metabolize carbs to power your muscles. It also produces hemoglobin, a protein that helps the red blood cells in your blood carry oxygen to your tissues and muscles.

When you have an iron deficiency, your body is robbed of oxygen. It also affects your power, stamina, and strength, particularly during intensive exercise, like running.

Most runners who experience low iron levels will find they have a dip in their performance levels when their iron is low.

How Much Iron Does A Runner Need?

The recommended daily iron intake for men is 8 – 10 mg, and for women is 15 – 18 mg. These needs increase to 15 – 19 mg during menstruation and 27 mg during pregnancy. Vegans and vegetarians need around double these amounts as the iron in their food sources is not optimally absorbed.

As a runner, depending on your mileage and intensity, your need for iron is around 1.3 – 1.7 more than the above amounts. So, if you are a non-running male, your need would be 8 mg. If you were to take up moderate-intensity running four times per week, you’d need a daily intake of 11 mg.

Does Running Cause Low Iron Levels?

Yes, it does.

Studies found that iron deficiency impacts around 50% of female and 17% of male runners. There are several reasons for this, including:


When you run, you sweat – or at least most of us do. When we sweat, we lose various vitamins and minerals, including iron. If you run longer distances or live in a hotter climate, this may be a significant contributor to low iron levels.

Higher Hepcidin

As we all know, running (and exercise in general) causes natural inflammation in your body. This inflammation causes the release of a hormone called hepcidin, which is basically an iron blocker. The release of this hormone means that no matter how much iron you take as a supplement or eat, it’s harder for your body to absorb iron.

Foot Strike Hemolysis

Here’s a fun fact: you can lose iron from your foot strike while running. This process is called foot strike hemolysis. When your feet hit the ground, your red blood cells can get damaged, which causes your hemoglobin levels to drop. If you run high mileage each week, you may find that food strike hemolysis is sapping your iron.

Regular Daily Iron Loss

Normal daily activities also impact your iron levels. You can lose iron through urination, GI tract processes, and menstruation. This regular daily iron loss occurs to everyone, runner or not.

Symptoms of Low Iron in Runners

Before we look at the symptoms of iron deficiency, it’s vital to understand that not every runner will experience all these symptoms. If you’ve noticed a change in your performance and have some of the symptoms below, consult your doctor and get properly tested. An iron supplement isn’t always the best fix, and too much iron can be toxic.

Here are the symptoms of low iron to keep a lookout for:

  • General fatigue (more than normal, as long as sleep is adequate)
  • Muscle weakness
  • Decrease in performance and capacity
  • Shortness of breath
  • Increased heart rate
  • Heavy periods (more than normal)
  • Dizziness
  • Headaches
  • Brittle nails
  • Extremities feel cold
  • Sick more often
  • Pale appearance
  • Dry, cracked lips
  • Crave non-food items (e.g., clay, ice, dirt, chalk)

Typically, the first symptom of iron deficiency is fatigue. If you’re struggling to maintain your regular pace or feel more tired than normal after your runs, this is a red flag. If you notice this fatigue is paired with any other symptoms above, get a blood test as soon as possible.

What is Anemia?

While iron deficiency and anemia are similar conditions, they have a few unique differences. Both involve having low ferritin levels (how well your body stores iron). But if you have anemia, it means you have low ferritin levels AND low hemoglobin levels. 

This is a very serious condition and shouldn’t be ignored. Having anemia as a runner can severely impact your running performance, take the fun and enjoyment out of running, and damage your overall health.

Should You Stop Running If You Have Low Iron?

If you suspect you have low iron levels, your doctor is the first person you should speak to.

Each runner is unique, and what works for one won’t necessarily work for another. Your doctor may suggest a short break from running to assess the impact on your iron. They may also recommend a change of distance or frequency.

How Can Runners Increase Iron Absorption

How much iron does a runner need?

You can do many things to increase your iron absorption without taking a supplement (always the last resort) and keeping up with your training plan.


This one may seem obvious (because it is), but luckily eating more iron-rich foods is the first thing most doctors will recommend. See our runner’s diet guide for some healthy ideas.

Best Iron-Rich Foods

As always, good nutrition is fundamental to good running.

The best foods to increase your iron are red meats. But there are so many other ways you can increase your iron intake. Some of the best sources include:

  • Seafood (oysters, clams, muscles)
  • Poultry and meats (beef, pork, lamb, etc.)
  • Egg (with yolk)
  • Lentils, beans, and legumes
  • Fortified grains (quinoa, bulgar wheat, barley)
  • Seeds and nuts
  • Oats
  • Soy products
  • Dried fruit and raisins
  • Vegetables (dark greens, peas, potatoes)

You should also consider using a cast iron skillet for cooking your food – these skillets add a few milligrams of iron to each meal, and every little bit counts. Ensure you include high-iron foods in every meal of the day, as this aids in adsorption.

You can do a few things to boost iron absorption during your meals, such as drinking orange juice or a vitamin C supplement, which increases iron absorption. Avoid milk or dairy when eating iron-rich foods. The calcium suppresses iron absorption.

Meal Timing

Increasing your iron intake doesn’t only mean eating high-iron foods. You also need to look at when you should eat them. Interestingly, the time of day greatly impacts how much of the iron you consume is absorbed. A study found that the optimal window for iron absorption is in the morning, straight after running.

The study observed that runners who consumed iron (supplement or food-based) within 30 minutes after a 90-minute run in the morning absorbed around 40% more iron than if they did the same thing in the afternoon. Hepcidin levels are higher in the afternoon, so afternoon runs may actually block iron absorption.

Try eating iron-rich meals in the morning after your exercise routine. After a few weeks, you should notice a bit more pep in your running step.

Choose a Quality Iron Supplement

The simplest and most effective way to ensure you get high levels of iron is by taking an iron supplement. The only issue with this is that around 70% of runners who use iron supplements experience GI side effects, including gas, bloating, cramps, and constipation.

If an iron supplement isn’t correctly formulated, the acid in your GI tract breaks down the iron. So, rather than being absorbed into your system, the iron leaves your body and causes havoc on its way out.

The best iron supplement you can use as a runner are those specially formulated to boost absorption and have been made specifically for runners.

Are You Getting Enough Iron?

Knowing how much iron you need as a runner is vital to your performance, health, and well-being. If you experience any of the symptoms we discussed, get a blood test and visit your doctor immediately.

Iron is an important part of your body’s proper functioning and helps you perform better as a runner.

Trust us – there’s no need to suffer through this; the solutions are simple.

Author Profile

Thalia Oosthuizen

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Thalia started running during the the pandemic as a way of getting out of the house. The running bug bit, and now much of her life revolves around everything to do with running - videos, podcasts, studies, books, articles, and interviews. She's also done several courses on running nutrition and mechanics to aid in her training and advising others.
Thalia Oosthuizen

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