The Hidden Performance Killer: Iron Status in Athletic Populations - Insights from the Innersight Podcast #25

In this episode of the Innersight Podcast, we revisit a crucial yet often misunderstood topic of iron, with a renewed focus on how it impacts athletic performance and overall wellbeing.

To shed light on this subject, we are joined by Dr. Claire Barrett, a senior specialist physician from the University of the Free State and a leading expert in blood health and iron deficiency.

Claire’s journey into this field began at home; as a mother to a high-performance swimmer, she observed firsthand how much advice and supplementation athletes receive, yet how rarely iron is discussed, even though it plays a critical role in endurance, energy levels and recovery. This gap in awareness led her to study the relationship between iron levels and athletic performance in depth.

Through clinical work and research, Dr. Barrett has seen what many overlook: even elite athletes can suffer from iron deficiency, and it often goes undiagnosed. The assumption that physically fit individuals are also biochemically healthy is misleading. Testing often misses the mark, with many people being told their results are "normal," despite suboptimal levels that impact performance and health.

One biomarker, ferritin, stands at the center of this issue. Ferritin reflects the body's iron stores, yet it is poorly understood even among healthcare professionals. Many patients (and practitioners) are unaware of what constitutes an ideal ferritin range, or how misleading standard reference ranges can be.

As we emphasize, this is not fringe science or advanced biohacking, it's the foundation of metabolic health. Optimizing iron levels should be seen as a first step in any health or performance journey, not an afterthought.

Iron Deficiency: Common Misconceptions and Why Early Detection Matters

Despite iron deficiency being the most widespread nutritional deficiency worldwide, it remains largely misunderstood. Medical training often overlooks practical guidance on recognizing and managing iron deficiency, leading to missed or delayed diagnoses.

One key misconception is that iron deficiency only needs to be screened when anemia develops, as indicated by low hemoglobin levels. In reality, by the time anemia is detected, iron depletion has often been ongoing for months or even years. This delay can have serious consequences for both athletes and the general population, as iron is essential for far more than just red blood cell production.

Another common error is the reliance on morphological blood indices, such as mean corpuscular volume (MCV) to guide iron testing. Waiting for these parameters to change means missing the opportunity for early intervention before symptoms worsen.

Further complicating diagnosis is the variability and inadequacy of laboratory reference ranges. Many doctors depend on automated lab flags to interpret test results; if a value isn’t flagged as abnormal, it is often overlooked. However, standard reference values are frequently too broad and not sensitive enough for early iron deficiency detection, particularly regarding ferritin, the primary marker of iron stores.

What Athletes Experience with Iron Deficiency

Iron deficiency in athletes often manifests as persistent fatigue, reduced exercise capacity, “brain fog,” and poor recovery, symptoms easily mistaken for overtraining or lack of rest. Neurocognitive effects such as low motivation, anxiety and depression are also common and can impact performance and enjoyment of sport.

Interestingly, athletes face unique challenges related to iron metabolism. Physical stress from intense training triggers the release of hepcidin, a hormone that reduces intestinal iron absorption, limiting how much dietary iron can be utilized, even if intake is adequate. Additionally, endurance athletes may experience microscopic blood loss from the gastrointestinal tract or through repetitive foot strikes (a phenomenon called “foot strike hemolysis”), further depleting iron levels.

Therefore, even well-nourished athletes can develop iron deficiency due to increased demands and physiological barriers.

Practical Testing Recommendations for Athletes

To effectively monitor iron status, athletes, especially female athletes, should have their ferritin levels tested regularly, ideally every six months. Testing should occur when the individual is healthy and not experiencing inflammation or recent illness, as ferritin is an acute phase reactant and can be falsely elevated during inflammatory states.

Iron studies should be performed while fasting and at the start of a training cycle to avoid confounding effects of recent intense exercise or supplementation. It is important for athletes and healthcare providers to understand these nuances to avoid misinterpretation of lab results.

Athletes should advocate for comprehensive iron testing, including ferritin and transferrin saturation, rather than relying solely on hemoglobin or standard blood counts. Early detection and management of iron deficiency can optimize performance, recovery and long-term health.

What is a Normal Ferittin Level?

Generally if your ferritin is less than 50, whether you’re a couch potato or a marathon runner, you are iron deficient, and that applies to everyone. When ferritin levels are between 50 and 100 this range is considered to be borderline; many experts believe ferritin should be at least 100, especially considering the pleiotropic effects of iron, not just its role in hemoglobin. We want iron stores to be full, ideally closer to 100, not as low as possible. The data supports 50 as a cutoff, but symptoms often start early because the bone marrow hoards iron to maintain hemoglobin. Once your hemoglobin drops, the body is essentially iron-starved.

Iron deficiency happens in four stages:

1. You might have odd symptoms like hair loss or mood changes while ferritin is low but hemoglobin normal

2. Bone marrow iron stores drop

3. Your MCV (mean corpuscular volume) starts to fall

4. Finally, hemoglobin drops, which is the last stage

   
   

Those early symptoms are mostly energy-related, and it’s important to understand why. Iron isn’t just for hemoglobin; it’s critical in mitochondria, the powerhouse of cells where ATP, the energy currency is made.

Without enough iron, mitochondria can’t work properly, no matter how good your diet or supplements are. That also affects muscle growth and maintenance, including respiratory muscles like your diaphragm, which are iron-dependent. Studies even show improved respiratory function in older people after correcting iron deficiency, which is hugely relevant for athletes who rely on good breathing.

Myoglobin, an iron-containing protein in muscles, is essential for function. Without iron, muscles get sore, tired and can’t perform well, leading to exhaustion. So it’s about more than just hemoglobin; iron is foundational to energy production and muscle function, especially in female athletes who are more at risk.

Regarding iron absorption issues in athletes with low-grade inflammation, screening is key, and every athlete should know their ferritin levels.

Iron Supplementation

• If oral supplements don’t work, we might need to consider intravenous iron, especially if ferritin remains low after three months of oral supplementation

• Athletes should take supplements right after training, which is when absorption is best. Avoid enteric-coated iron tablets; they’re expensive and less effective because iron is absorbed mainly in the duodenum

• If oral iron causes nausea or can’t be tolerated, then intravenous iron should be considered

  
  

• Testing is essential to confirm if the treatment works, and if not, deeper investigation is needed to rule out causes like GI bleeding or other pathology

  
  

• Emphasis must be placed on retesting after supplementation; don’t just give iron and assume the problem is fixed. Iron deficiency might be due to exercise physiology, but it can also mask serious health issues

In Conclusion:

For athletes, everyone, not just women, should test their ferritin regularly, six monthly or yearly, and act on the results.

For medical professionals, test ferritin, retest after treatment and investigate underlying causes if levels don’t improve.

Read our other Iron blog post with Prof Vernon Louw at the link below ⬇️

🔗 https://www.innersight.co.za/post/unravelling-iron-with-professor-vernon-louw-insights-from-the-innersight-podcast-13

#Iron #IronDeficiency #IronLevels #IronDeficiencyAnemia #Ferritin #AthleteHealth #SportsPerformance #OptimalPerformance #SportsMedicine #ExerciseScience #Innersight