Is Ferritin Eisenmangel useful for Sport?

Whether ferritin measurement for detecting iron deficiency is useful in sports is not a simple yes or no. Ferritin is the primary iron storage protein; low levels indicate depleted iron stores. Iron deficiency—even without anemia—can impair endurance performance, oxygen transport, and recovery because iron is critical for hemoglobin synthesis and mitochondrial energy metabolism. Studies show that endurance athletes (e.g., runners, cyclists) are at increased risk for subclinical iron deficiency due to iron losses through sweat, hemolysis, and gastrointestinal bleeding. Thus, ferritin screening is a standard tool in sports medicine. However, ferritin is an acute-phase reactant: inflammation, infection, or recent intense exercise can falsely elevate it, so concurrent CRP measurement is advisable. The optimal ferritin target for athletes is debated—commonly >30 ng/mL is considered adequate, but some experts recommend >50 ng/mL for peak performance. Evidence that iron supplementation improves performance in non-anemic athletes with low ferritin is moderate and inconsistent. In summary, ferritin is a useful but imperfect marker; interpretation requires clinical context. Routine screening without symptoms or risk factors is not universally endorsed by guidelines.