Iron deficiency, with or without anaemia, is one of the most common medical problems in athletes and a frequent cause of fatigue and disappointing performance.
- •Anaemia is a haemoglobin concentration below the reference range for the person's age, sex and physiological state, which lowers the blood's oxygen-carrying capacity.
- •Iron deficiency without anaemia is more common in athletes and more easily missed: iron stores are low but haemoglobin is normal.
- •A mild fall in measured haemoglobin is often a normal adaptation to endurance training: an expanded plasma volume lowers the concentration while total red cell mass is normal or increased.