CONCLUSIONS
Sports cardiology screening of young athletes is essential to discover not only life‐threatening abnormalities but also performance limiting factors, such as ID. In young athletes, ID is common and more pronounced in the youngest age groups; therefore, the early screening of ID is essential. In our randomized placebo‐controlled trial, after the 3‐month oral iron supplementation the ferritin levels increased in the iron group without significant performance improvement between the placebo and the iron group; however, only a small portion of the athletes achieved the expected cut‐off value. Our study highlights the need of age‐corrected ferritin cut‐off value or using a combined interpretation of the iron panel in young athletes. Further studies are needed to establish the optimal iron supplementation form, period, and dose in athletes.