Why Is Iron Important For Athletes? 4 Reasons to Top Up Your Intake

Whether you’re a long-distance runner, powerlifter, or boxing champ, there’s a pretty hefty list of supplements that can help your performance. BCAAs, beta-alanine, creatine, and the list goes on.

On top of that, we also have the protein, carbs, and fats—the macronutrients—that are essential to your performance and recovery. But what we rarely hear about for athletic performance is the smaller guys—the micronutrients.

They may only be required in small amounts, but these guys can make or break your performance on a whole new level. They’re the guys needed to ensure muscles contract and relax, produce sufficient energy to help you train, and ensure your body has what it needs to repair after intense training sessions. Without the micronutrients, your performance is virtually non-existent.

But of those micros, there’s one that shines for athletes—iron. While you may be pumping a lot of iron in the weight room, you may not be getting enough in your diet. So, right now, we’re covering what you need to know about iron and athletic performance and why you need to top up your intake.

What Is Iron And Why Do We Need It?

Iron deficiency is one of the most common nutrient deficiencies worldwide, with more than 15% of the global population not having adequate levels ¹. Iron deficiency happens when the body’s iron stores become depleted, and there is a lack of iron transport to tissues. As a result, oxygen transport capacity decreases and there is a significant reduction in oxidative capacity at the cellular level of functioning.

The reason why is because iron is a critical nutrient required for the production of hemoglobin—the body’s oxygen transport molecule; it forms the ‘heme’ component of hemoglobin. It is also required to form myoglobin, the iron- and oxygen-binding molecule found in muscle cells that functions to supply oxygen to myocytes ². Because of this role in oxygen transport, iron plays a key role in energy metabolism.

On top of that, it’s also involved in immune development and function as a component of proteins and enzymes that mitigate oxidative stress, along with supporting the synthesis of DNA, connective tissue, and certain hormones ^{1, 3}. As such, a deficiency of iron not only impairs athletic performance but also leads to impaired immune function and other physiologic dysfunction.

Iron And Athletic Performance

Generally speaking, iron gets put on the sidelines as one of the nutrients needed for athletic performance, but it needs to be center field. Without sufficient iron stores, the muscles don’t have the oxygen they need to function, and performance will take a major hit.

Studies suggest that exercise itself may alter iron status, and this alteration could be detrimental to athletic performance or to the health of the athlete ¹.

While we may not think much about how iron contributes to our performance when we have sufficient stores, low levels of heme iron—the form present in animal tissues—can profoundly alter physical work performance by decreasing oxygen transport to active muscle tissues.

But it’s not just heme iron. Non-heme iron and its associated enzyme systems play a major role in athletic performance, and deficits of these enzymes can impair performance.

For example, research finds that maximal oxygen uptake (V̇O2max) is largely determined by the oxygen-carrying capacity of the blood and is linked to levels of iron and the degree of anemia ¹.

However, impaired endurance performance at low intensities is ‘more closely related to tissue iron concentrations because of the strong association between the ability to maintain prolonged submaximal exercise and the activity of iron-dependent oxidative enzymes’ ¹.

Research also shows that decreases in myoglobin and other iron-containing proteins in skeletal muscle in people with iron-deficient anemia causes a decline in muscle aerobic capacity ^{4, 5}.

4 Reasons For Athletes To Boost Iron Levels

With all of that said, here’s why you need to bump up your iron stores!

1. Energy production: Iron is a major component of hemoglobin, myoglobin, cytochromes, and various enzymes in myocytes, all of which are involved in the transport and metabolism of oxygen for aerobic energy production during endurance activities ⁶. Iron is also required for the oxidative production of adenosine triphosphate (ATP) in the electron transport chain that relies heavily on non-heme iron-sulfur enzymes and heme-containing cytochromes ⁷. Low iron levels are generally linked to impaired aerobic power, with the magnitude of performance decrements related to the severity of iron deficiency.
2. Support aerobic pathways: Along with its role in energy production, reduced oxygen transport to active skeletal muscle due to low iron levels may place higher demands on anaerobic metabolism, which may have adverse outcomes for performance, including lower blood pH, depletion of muscle glycogen stores, and more ⁷. Because endurance athletes rely on aerobic metabolism, iron deficiency generally has a profound impact on endurance athletes’ performance.
3. Supports muscular performance: Because of its role in energy production, iron deficiency anemia has been shown to impair muscular performance and accelerate the onset of fatigue ⁶. A 2003 study of twenty iron-depleted, nonanemic women received iron supplementation or a placebo for six weeks alongside a protocol integrating 2–3 second maximal voluntary static contractions (MVCs) with dynamic knee extensions ⁸. The study showed that iron supplementation was linked to a significant improvement in muscle fatigability, suggesting a direct role of tissue iron status on the extent of muscle fatigue experienced during exercise.
4. Improve mood: Mood may not be the first thing you think about with respect to performance, but have you ever tried training when you’re angry, upset, frustrated, or irritable? It generally doesn’t go too well, and it usually affects your level of motivation. That’s because iron is required for several enzymes involved in neurotransmitter synthesis, including serotonin, dopamine, and norepinephrine, all of which are involved in regulating mood, neuronal activity, and anxiety ⁹. Low levels of iron are usually linked to low serotonin, which impacts mood as well as sleep ¹⁰.

While iron is critical for several aspects of an athlete’s performance, keep in mind that because of monthly menses, female athletes often have an increased requirement for iron, so if dietary intake is low, supplementation is a must.

Final Thoughts

Regardless of the cause, iron deficiency is a condition that athletes don’t want to deal with. An essential component of hemoglobin, myoglobin and several iron-containing respiratory enzymes, iron is essential for energy production and an athlete’s performance and recovery.

Even small decrements in hemoglobin can significantly affect physical performance, so take it from us when we tell you that you want to make sure you’re doing whatever is necessary to avoid low iron status if you wish to maximize performance.