Thalassemia is a type of hemoglobinopathy, an inherited blood disorder associated with reduced production of alpha or beta-globin chains, which form hemoglobin. Thalassemia is fairly common, especially in the Mediterranean, Asia, Africa, and the Middle East, and is quite rare in central or northern Europe [1]. The condition is usually diagnosed after birth; sometimes the symptoms and signs associated with the diagnosis occur later in adolescence or adulthood [1], [2], [3]. Thalassemia range in severity from asymptomatic conditions (thalassemia trait) to mild (thalassemia minor) or more severe ones (thalassemia intermedia or major). The thalassemia trait is when a person is not diagnosed with the condition but carries one of the mutated genes [4].

A quantitative reduction in beta-globin chains caused by gene mutations at the transcriptional or even post-transcriptional level causes β-thalassemia. The main gene mutation causing the disease is the HBB gene. A minimal deficit of beta-globin subunits is called β-thalassemia, and a total deficit is called β0-thalassemia. The excessive unmatched α-globin subunits fail to form viable tetramers and precipitate in red cell precursors in bone marrow, resulting in disruption of erythroid precursors and hence the ineffective erythropoiesis that underlies β-thalassemia [2].

HbA is dominant adult type of hemoglobin. β-thalassemia individuals exhibit elevated values of HbA2 (reference values of 2.5–3.5%) and elevated values of fetal hemoglobin (HbF – the tetramer consists of 2 α-units and 2 γ-units) [5], [6]. Therefore, elevated HbA2 is the key blood parameter for identifying β-thalassemia carriers and plays a key role in screening programs for β-thalassemia.

The exercise capacity is markedly reduced in patients with severe forms of thalassemia due to tissue hypoxia and severe anemia [7]. In contrast, thalassemia minor and more common thalassemia trait generally create mild anemia with mild microcytosis (MCV < 65 fL) and affected athletes might be often asymptomatic and are not at risk for thrombotic events and painfull crises [8]. Patients with less severe forms of thalassemia are prone to higher RBC rigidity which might lead to microcirculation disorders but are not furthermore impaired in response to exercise [9]. The participants in that study reached similar peak values in maximal exercise performance test as healthy individuals. On the contrary, another study (36 subjects) dwelving into β-thalassemia and muscular deconditioning suggests that the thalassemic individuals show lower muscular strength compared to healthy controls. Authors suggest an altered neuromuscular environment, as indicated by the lower muscle fiber conduction velocity, which suggests a smaller average muscle fiber size. All these musculoskeletal manifestations might occur due to chronic tissue hypoxia, caused by reduced hemoglobin quality [10].

We had a unique opportunity to investigate the symptoms and hematological parameters, muscle morphology, and physical performance parameters of a 79-year old male master athlete diagnosed with heterozygote β-thalassemia minor and despite that is able to run 10 km below a respectable 50 min, consistently run a half-marathon below 2 hours, and full-marathon races under 3.5 hours and still actively trains for these endurance events in a volume higher than 150 min a week. Besides his international achievements at the world level up to now he is ranked No. 1 in Slovakia and Czech Republic in his category.