The Mega Mineral You Might Be Missing

Exhausted? Check your iron. Athletes, especially women, are often running low on this performance-making or -breaking nutrient. Here's why.

Last updated: December 21, 2020
Do I Need More Iron in My Diet?

You're training hard, but the quality of your workouts is going down and your recovery time is going up. You may need to pump more iron—the mineral, that is.

"Red blood cells require iron to make haemoglobin, which carries oxygen through the blood to all of your tissues and cells", says Robin Foroutan, RDN, an integrative dietitian in New York City and spokesperson for the Academy of Nutrition and Dietetics. "Without adequate supplies of iron, you can't make enough haemoglobin, which can cause your red blood cells to be the wrong size or colour". Fewer quality red blood cells means there's less oxygen circulating, causing exercise, work and projects to feel harder than usual.

While it's considered a "trace" mineral, meaning you need only small amounts of it, iron is just as vital to the way your body functions as any of the seven major, or macro, minerals are. And despite the fact that we don't need much iron, exercising and eating a healthy diet can actually make it hard to get enough, as you're about to learn.

While it's considered a "trace" mineral, meaning you need only small amounts of it, iron is just as vital to the way your body functions as any of the seven major, or macro, minerals are.

Digging Into the Iron-Deficiency Issue

Iron can play hard to get, especially with super-active people. So much so, in fact, that according to a 2019 review published in the "European Journal of Applied Physiology", 15 to 35 percent of female athletes, and 5 to 11 percent of male athletes, are deficient. (Women can be at a higher risk because of their periods).

Why is it so elusive? If you're cutting calories or eating a vegetarian or vegan diet, you may not be eating enough foods that contain iron. You also might not be absorbing all of the iron you are consuming. Add heavy workouts into the mix, and you could actually be losing some of the iron you're taking in. "Endurance athletes, like runners, damage red blood cells when they run on very hard surfaces, particularly with poor-quality shoes", says Foroutan. (The less cushioning and support you have, the harder the impact and the more red blood cells you can injure, which take some iron away with them). You also lose some iron in super-sweaty workouts—such as HIIT, endurance or hot sessions—she says, but that's typically not enough to cause a deficiency on its own.

"Iron deficiency develops in stages", says Floris Wardenaar, PhD, an assistant professor of sports nutrition at Arizona State University. "In the beginning [at what's called 'mild deficiency'], your iron stores become depleted, but you still have enough to distribute oxygen throughout the body, so you might not even notice", he says. "Then, as iron supplies continue to dwindle, red blood cells start to become affected [at marginal deficiency]". You may or may not feel tired, or see changes in your performance or recovery. Chronic gastrointestinal issues can be a sign you aren't properly absorbing nutrients. If a marginal deficiency is left unchecked, you could develop the most extreme version, iron-deficient anaemia, which means you can't make enough quality red blood cells. And without quality red blood cells, Wardenaar says you may experience fatigue, pale skin, cold hands and feet, a sore tongue, dry skin and hair, and brittle nails.

If you notice any of these symptoms, especially unexplainable fatigue, call your doc and request a complete blood count, as well as tests for your levels of ferritin (a protein that stores iron in the body) and total iron-binding capacity, says Foroutan. Note that if your lab results look normal when they come back but you still feel off, you should ask about tests that can dig even deeper.

How to Increase Your Intake

Here's a quick rundown of where to get your iron fix from, and how much you need. For starters, there are two types of iron: haem, which comes from animals, particularly red meat and poultry, and non-haem, which is found in plants. "The iron in haem foods tends to be easy to absorb", says Foroutan. Non-haem iron, however, has natural plant compounds attached to it that are hard to break down, she says, which can make absorption more difficult.

The recommended daily intake is 8 milligrams for men and 18 milligrams for women (or 27 if you're pregnant), according to the US National Institutes of Health (NIH). If you're vegetarian, you need almost twice that amount, per the NIH, to make up for poor absorption. Eating spinach and other dark leafy greens, dried apricots and peaches, peas, beans, lentils and hearts of palm can help you pack in more of the mineral. Check in with your doc before you start upping your intake by crazy amounts or even considering a supplement, because 45 milligrams or more of iron, unless prescribed, could cause stomach issues.

To help your body better absorb non-haem iron, pair it with haem sources by, say, adding a little steak to your spinach and lentil bowl, as the former improves the absorption of the latter. Or, if meat's not your thing, combine iron-rich foods with those containing vitamin C, such as peppers, tomatoes, citrus fruits and strawberries. "Vitamin C kicks off a chemical process that helps break those strong plant compounds down, so you get more iron from them", says Adam Feit, the performance-nutrition coordinator at Precision Nutrition. Interestingly, the tannins in tea and coffee can limit iron absorption, so try to avoid those within 60 to 90 minutes of eating iron-rich foods, adds Wardenaar.

Once you get your iron levels on point, you should start feeling better within a few days, says Wardenaar. And you'll likely never want to go back to leaving it off your plate (or barbell).

Do I Need More Iron in My Diet?

Take It Further

For more expert-backed guidance on recovery, as well as mindset, movement, nutrition and sleep, check out the Nike Training Club App.

Take It Further

For more expert-backed guidance on recovery, as well as mindset, movement, nutrition and sleep, check out the Nike Training Club App.

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