Iron status was studied in 126 female endurance athletes and 52 control subjects, all aged 16–20 years. The study aimed at identifying factors responsible for iron deficiency. Twenty-six percent of athletes and 50% of controls had latent iron-deficiency without anemia symptoms. A too low intake of iron (especially heme iron: 0.3 mg daily), and of nutrients influencing iron metabolism, were identified as main causes of iron deficiency in control subjects. In athletes, whose iron intake was sufficient (14.6 mg), the principal cause of iron deficiency were blood losses due to menstruation. High level of physical activity, expressed as training volume and experience, did not adversely affect iron stores, as these were higher than in control subjects and the incidence of iron deficiency was much lower than in the control group. It was concluded that an increased intake of iron and of dietary factors involved in iron metabolism prevented possible exercise-induced losses of iron in young athletes.
Jadwiga Malczewska, Grzegorz Raczynski and Romuald Stupnicki
Katarzyna Milde, Pawel Tomaszewski and Romuald Stupnicki
The aim of the study was to assess physical fitness of girls with Turner syndrome (TS) and to determine the relative contributions of age, body height, and body mass to performance in fitness tests. Girls with TS aged 10–18 years (n = 184), and age- and stature-matched healthy controls (n = 280) were studied with the use of the EUROFIT test battery. Girls with TS were significantly inferior to the control group in maintaining balance, standing broad jump, sit-ups, shuttle run, and endurance shuttle run (p < .001). No significant differences were found for plate tapping, but girls with TS were superior to their healthy mates (p < .001) in handgrip, sit-and-reach, and bent-arm hang. Unlike controls, body height in girls with TS had significant effects on handgrip strength (positive) and on plate tapping speed (negative), other contributions being relatively similar in both groups. It thus seems that the somatic specificity of girls with TS explains most differences in motor fitness. The identified motor deficiencies of girls with TS call for undertaking steps toward attracting those girls to motor activities.
Grzegorz Raczyński, Jan Czeczelewski, Maciej Skład and Romuald Stupnicki
The aim of the study was to establish the relationships between energy intake and dietary quality with somatic variables and physical fitness. Energy intake and nutrition quality were assessed from 24-hr dietary recall questionnaires, and physical fitness was measured by applying the EUROFIT tests. Interrelationships between all those variables (simple, partial, and multiple correlation coefficients) were computed from standardized values. The somatic and physical fitness variables related more strongly on the nutrition quality than on the energy intake. Well-nourished children were taller, heavier, and more physically fit than the poorly nourished ones. We believe that dietary quality affected physical fitness indirectly by influencing somatic development. Energy intake did not contribute significantly to the total variance of the physical fitness factor.
Jadwiga Malczewska, Beata Szczepańska, Romuald Stupnicki and Witold Sendecki
The transferrin receptor-ferritin index (sTfR/logFerr) was determined in 131 male and 121 female athletes in order to assess the frequency of iron deficiency (threshold value of that index taken as 1.8). Blood was drawn for determining morphological indices as well as sTfR, ferritin, iron, total iron binding capacity (TIBC), and haptoglobin. A significantly (p < .01) higher incidence of iron deficiency was observed in women (26%) than in men (11%). The iron deficiency was latent, since no subject was found to be anemic. The plasma iron was significantly lower and TIBC higher (p < .001) in both iron-deficient subgroups than in the non-deficient ones. This confirmed the latent character of iron deficiency. Some hematological indices (Hb, MCH, MCHC, MCV) were significantly lower in iron-deficient female athletes than in male athletes, which suggested a more profound iron deficiency in the former. The sTfR/logFerr index might thus be useful in detecting iron deficiency in athletes, especially in those with erythropoiesis disorders, since physical loads may affect the widely used ferritin levels.