Iron and sport: why is it essential for performance?
Iron is essential for athletes. Learn why, how to prevent deficiency, and how to optimize your performance through an iron-rich diet.
Table of Contents
Key Takeaways:
Iron is fundamental for oxygen transport and energy production in athletes.
Iron deficiency particularly affects endurance athletes and women.
There are two types of iron: heme (meat, fish) and non-heme (plant-based, eggs).
Iron absorption depends on diet, lifestyle, and the form chosen (bisglycinate is highly effective).
Adequate iron intake optimizes performance, recovery, and prevents fatigue.
Introduction
What is the general role of iron?
Iron is an essential mineral for the human body. It primarily contributes to the formation of hemoglobin, a protein found in red blood cells. Hemoglobin transports oxygen from the lungs to muscles and organs. Without sufficient iron intake, oxygen circulation is less efficient, and performance suffers.
Iron also plays a role in:
Energy production within muscle cells,
Immune system function,
Synthesis of certain neurotransmitters, essential for focus and motivation.
Iron ensures vitality, endurance, and recovery capacity. For athletes, whose oxygen needs soar during effort, deficiency can quickly limit progress.
What can cause iron deficiency?
Iron deficiency may result from:
Inadequate dietary intake (especially in vegetarian or vegan diets),
Increased losses through menstruation or blood loss),
Intense training, which increases iron requirements),
Absorption issues linked to certain digestive disorders.
Why is it even more crucial for endurance athletes?
Endurance athletes rely heavily on oxygen transport to sustain long efforts. Iron deficiency can lead to:
Reduced aerobic capacity,
Early fatigue,
Longer recovery times,
Impaired immune function.
Therefore, monitoring iron status is crucial for athletes who engage in high-volume training.
Consequences of iron deficiency
Iron deficiency, if left unchecked, can lead to anemia. Symptoms include:
Chronic fatigue,
Decreased concentration and alertness,
Weakness and lower physical performance,
Increased risk of infections.
Different types of iron: heme vs non-heme
Iron exists in two forms:
- Heme iron: Found in animal products (meat, fish, poultry). Highly absorbable.
- Non-heme iron: Found in plant-based foods (legumes, spinach, nuts) and eggs. Absorption can be lower and depends on diet composition.
In food, there are two main forms of iron:
Heme iron: Found in red meat, poultry, and fish. Absorption rate: 15–35%.
Non-heme iron: Found in vegetables, legumes, and fortified foods. Absorption rate: 2–20%, influenced by other nutrients.
How to increase iron intake through diet?
- Include heme iron sources regularly (lean red meat, fish, poultry).
- Combine non-heme iron foods with vitamin C-rich foods to improve absorption (e.g., spinach + citrus).
- Avoid excessive tea or coffee during meals, as they reduce iron absorption.
- Monitor iron levels with blood tests if needed.
Factors affecting iron absorption
- Vitamin C enhances non-heme iron absorption.
- Calcium, polyphenols (tea, coffee), and phytates (in legumes, grains) inhibit absorption.
- Cooking in cast iron pans can increase iron content in foods.
- Digestive disorders can reduce absorption efficiency.
Iron bisglycinate: a reference form
Iron bisglycinate is a form of iron chelated with glycine. Advantages:
- Highly bioavailable and well tolerated by the digestive system,
- Less risk of constipation or stomach discomfort compared to other iron forms,
- Ideal for athletes needing supplementation.
When to consider supplementation? Precautions
Iron supplementation should be considered if dietary intake is insufficient and/or blood tests indicate deficiency. Important precautions:
- Always consult a healthcare professional before starting supplementation,
- Do not exceed recommended doses to avoid toxicity,
- Prefer forms with good tolerability (like bisglycinate) to avoid digestive discomfort.
Conclusion
Iron is a key mineral for athletes, especially those engaged in endurance sports. Maintaining adequate iron intake through diet or supplementation when necessary helps optimize performance, reduce fatigue, and support recovery. Monitoring iron status and choosing highly bioavailable forms ensures effective and safe supplementation.
SOURCES
- Beard, J. L. (2001). Iron biology in immune function, muscle metabolism and neuronal functioning. The Journal of Nutrition.
- Peeling, P. et al. (2007). Iron status and the endurance athlete. Sports Medicine.
- McClung, J. P., & Gaffney-Stomberg, E. (2010). Iron and exercise. Journal of Trace Elements in Medicine and Biology.
- Hemilä, H., & Louhiala, P. (2012). Vitamin C and iron absorption. Nutrition Reviews.
