Effects of exercise on the markers of iron status in serum of cross-country skiers

The study aim was to assess the within-subject, day-to-day variability for ferritin and soluble transferrin receptor (sTfR) concentrations in serum of 6 female and 8 male cross-country skiers aged 16-18 years under a regular training regimen throughout 8 consecutive days. The concentrations of iron status variables and creatine kinase (CK) activities were adjusted to plasma volume changes. Mean ferritin concentrations were 30.6 • 1.142[sup]±1[/sup] and 22.6 • 1.167[sup]±1[/sup] μg/l for men and women, respectively, the average within-subject, mean day-to-day variability coefficients (CV) being 13.4% in men and 15.2% in women. Mean sTfR was 2.14 • 1.050[sup]±1[/sup] and 2.62 • 1.047[sup]±1[/sup] mg/l, respectively, and mean day-to-day CV 6.5% and 4.6%. Mean CV for sTfR/logFerr were 6.0% and 7.4%, respectively. Neither index correlated with training loads or CK activities. Thus, the training performed once daily had no significant effect on ferritin concentrations on the following morning, so ferritin alone may prove insufficient in detecting iron deficiency in endurance athletes. The low variability of sTfR under endurance loads made it useful in detecting iron deficiency together with ferritin and the sTfR/logFerr index. Adjusting the concentrations of ferritin and sTfR by changes in plasma volume might be recommendable for endurance athletes

Expression of SCGB1C1 gene as a potential marker of susceptibility to upper respiratory tract infections in elite athletes : a pilot study

High levels of exercise in athletes result in temporary immunosuppression, which could increase the susceptibility to upper respiratory tract infections. Understanding of immunological mechanisms responsible for this phenomenon could enable optimization of training schemes for elite athletes and avoidance of infection-related episodes of absence during sports championships. The aim of this study was to detect genes that may be responsible for modulation of individual susceptibility to infections. The blood and saliva samples were collected from 10 healthy, medically examined kayakers (4 females and 6 males) aged 24.7 ± 2.3 years. All samples were taken in the morning, after overnight fasting, in a seated position. The ELISA method was used to determine the levels of secretory immunoglobulin A (sIgA) and interleukin 5 (IL-5). Whole genome expression in blood was assessed using microarrays. The study did not reveal any significant correlation between genome expression and sIgA concentration. However, low expression of a gene involved in protection against the common cold – secretoglobin 1C1 (SCGB1C1) – was detected in athletes with high IL-5 concentrations (corrected p=0.00065; fold change=3.17). Our results suggest that blood expression of the SCGB1C1 gene might be a marker of susceptibility to upper respiratory tract infections in athletes

Vitamin D Status and its Relation to Exercise Performance and Iron Status in Young Ice Hockey Players

Objectives The aim was to examine the association between serum vitamin D concentration and isometric strength of various muscle groups, vertical jump performance, and repeated sprint ability in young ice hockey players. The secondary aim was to determine the association between vitamin D deficiency and indices of iron status. Methods Fifty male ice hockey players (17.2±0.9 years) participated in this cross-sectional study. Exercise performance was evaluated using isometric strength measures of upper and lower extremities, vertical jump performance and repeated sprint ability (RSA). Blood samples were collected for the determination of serum 25-hydroxyvitamin D (25(OH)D) and multiple indicies of iron status. Results The mean serum 25(OH)D concentration was 30.4 ng-ml-1 and ranged from 12.5 to 91.4 ng-ml-1. Eleven participants (22%) had vitamin D deficiency and 20 athletes (40%) had vitamin D insufficiency. Serum 25(OH)D concentration was not positively correlated with isometric muscle strength, vertical jump performance, or RSA after adjusting for age, training experience, fat mass, fat free mass and height. Serum 25(OH)D concentration was not associated with indices of iron status. Conclusion Vitamin D insufficiency is highly prevalent in ice hockey players, but 25(OH)D concentration but it is not associated with exercise performance or indices of iron status

Total hemoglobin mass, aerobic capacity, and hbb gene in polish road cyclists

The relationship between genes, amount of hemoglobin, and physical performance are still not clearly defined. The aim of this study was to examine the association between-551C/T and intron 2, +16 C/G polymorphisms in the beta hemoglobin (HBB) gene and total hemoglobin mass (tHbmass) and aerobic capacity in endurance athletes. Total hemoglobin mass and aerobic capacity indices, i. e.,VO2max, oxygen uptake at anaerobic threshold (VO2AT), maximal power output (Pmax), and power at anaerobic threshold (PAT) were determined in 89 young road cyclists, female (n = 39) and male (n = 50), who were genotyped for 2 polymorphisms in the HBB gene. The relative values of aerobic capacity indices differed significantly among intron 2, +16 C/G polymorphisms of the HBB gene only in female cyclists; athletes with GG genotype had significantly higher values of V O2max (p = 0.003), VO2AT (p = 0.007), PAT (p = 0.015), and Pmax (p = 0.004) than C carriers. No relationships were found between the C-carrier model (CC + CG vs. GG in the case of intron 2, +16 C/G and CC + CT vs. TT for -551 C/T polymorphisms of the HBB gene) and relative values of tHbmass. Our results demonstrated that the HBB gene could be related to aerobic capacity, but it seems that it does not result from an increase in the amount of hemoglobin in the blood

Utility of Novel Hypochromia and Microcythemia Markers in Classifying Hematological and Iron Status in Male Athletes

In athletes, no reliable indices exist for an unambiguous evaluation of hematological and iron status. Therefore, the utility of some new red blood cell (RBC) parameters was explored in 931 elite male athletes aged 13–35 years. To diagnose iron status, the values of ferritin and soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), and basic blood morphology were determined in blood. The new hematological markers included among others: mean cellular hemoglobin content in reticulocytes (CHr), percentage of erythrocytes (HYPOm) and reticulocytes (HYPOr) with decreased cellular hemoglobin concentration, percentage of erythrocytes (LowCHm) and reticulocytes (LowCHr) with decreased cellular hemoglobin content, mean volume of reticulocytes (MCVr), and percentage of erythrocytes with decreased volume (MICROm). Despite adverse changes in reticulocyte hypochromia indices (CHr, LowCHr, HYPOr; p < 0.001) in the iron depletion state, the area under the receiver operating characteristic curve (AUC-ROC) values calculated for them were relatively low (0.539–0.722). In iron-deficient erythropoiesis (IDE), unfavorable changes additionally concern microcythemia indices in both reticulocytes and erythrocytes (MCVr, MCV, MICROm, and red cell volume distribution width—RDW), with especially high values of AUC-ROC (0.947–0.970) for LowCHm, LowCHr, and CHr. Dilutional sports anemia was observed in 6.1% of athletes. In this subgroup, only hemoglobin concentration (Hb), hematocrit (Hct), and RBC (all dependent on blood volume) were significantly lower than in the normal group. In conclusion, the diagnostic utility of the new hematology indices was not satisfactory for the detection of an iron depletion state in athletes. However, these new indices present high accuracy in the detection of IDE and sports anemia conditions

Evaluation of dietary intake of vitamins and minerals in 13-15-years-old boys from a sport school in Warsaw

Background. Insufficient intake of vitamins and minerals, in teenagers engaged in physical activity increases the risk of health disorders. Objective. The aim of this study was to evaluate selected vitamins and minerals intake in 13-15 -year-old boys from sport school. Material and methods. The study of dietary intake was conducted among 44 boys from the School of Sport Championship (SSC). Nutritional data was collected using 24-hour recall for 3 days of week. Daily intake of minerals: sodium, potassium, calcium, phosphorus, magnesium, iron, zinc, copper, iodine and vitamins: A, E, D, B1, B2, B6, B12, C, folate and niacin was estimated. The probability of insufficient intake of nutrients in relation to the standard levels: Estimated Average Requirement (EAR) or Adequate Intake (AI) as well as excessive intake of them in relation to the Tolerable Upper Intake Level (UL) were assessed. Results. The highest percentage of insufficient intake concerned vitamin D (100%), potassium (69%), folate (53%), and calcium (50%), slightly lower of magnesium (27%), vitamins C (24%) and E (15%). The risk of inadequate intake of other minerals: sodium, copper, iron, zinc, phosphorus, iodine and vitamins: B6, B1, B2, A, B12, niacin, was relatively lower and amounted from 0.3% to 5.4%. The disturbingly high probability of exceeding the UL for sodium (99.5%) was observed. Conclusions. A significant disproportion between the mean intake and the percentage of inadequate diets indicates a large diversity in the intake of vitamins and minerals in the group of studied boys, what was the reason of unbalanced diet. The insufficient intake concerns especially vitamin D, potassium, folate, calcium and a lesser extent magnesium, vitamins C and E. Sodium intake was disturbingly high. In order to avoid nutritional mistakes in the future education on the rational nutrition among students, their parents, and teachers is necessary.Wprowadzenie. Niewystarczające spożycie witamin i składników mineralnych wśród, nastoletniej młodzieży obciążonej wysiłkiem fizycznym zwiększa ryzyko wystąpienia zaburzeń w stanie zdrowia. Cel. Ocena spożycia witamin i składników mineralnych przez trenujących chłopców w wieku gimnazjalnym. Materiał i metody. Badaniami objęto 44 chłopców w wieku 13-15 lat ze szkoły mistrzostwa sportowego. Dane o spożyciu zebrano na podstawie wywiadów z ostatnich 24 godzin poprzedzających badanie, z 3 dni tygodnia. Obliczono spożycie składników mineralnych: sodu, potasu, wapnia, fosforu, magnezu, żelaza, cynku, miedzi, jodu oraz witamin: A, E, D, B1, B2, B6, B12, C, niacyny i folianów. Ponadto oceniono prawdopodobieństwo niedoborowego spożycia składników pokarmowych w relacji do poziomów norm średniego zapotrzebowania grupy (EAR) lub wystarczającego spożycia (AI), oraz nadmiernego ich spożycia w stosunku do najwyższego tolerowanego poziomu spożycia (UL). Wyniki. Najwyższe ryzyko niedostatecznego spożycia dotyczyło witaminy D (100%), potasu (69%), folianów (53%) i wapnia (50%), natomiast nieco niższe, magnezu (27%), witamin: C (24%) i E (15%). Ryzyko niedostatecznego spożycia pozostałych składników mineralnych: sodu, miedzi, żelaza, cynku, fosforu, jodu i witamin: B6, B1, B2, A, B12, niacyny było stosunkowo niższe i mieściło się w zakresie od 0,3% do 5,4%. W badanej grupie stwierdzono niepokojąco wysokie prawdopodobieństwo przekroczenia normy UL na sód (99,5%). Wnioski. Znaczna dysproporcja między średnim spożyciem a odsetkiem diet niedoborowych, świadczy o dużym zróżnicowaniu spożycia witamin i składników mineralnych w badanej grupie chłopców co było przyczyną niezbilansowania diety. Ryzyko niedostatecznego spożycia dotyczyło w szczególności witaminy D, potasu, folianów, wapnia, a w mniejszym stopniu magnezu, witaminy C i E. Niepokojąco wysokie było spożycie sodu. W celu uniknięcia błędów żywieniowych w przyszłości, istnieje potrzeba edukacji uczniów oraz ich rodziców i nauczycieli w zakresie racjonalnego żywienia

Is it sensible to administer food supplements to Polish elite weightlifters on a training camp?

Badania, miały na celu sprawdzenie zasadności stosowania odżywek przez reprezentantów kadry narodowej podnoszenia ciężarów. Przebadano 13 zawodników przebywających na zgrupowaniu treningowym pod kątem spożycia energii i wybranych składników odżywczych. Badania przeprowadzono na podstawie indywidualnych wywiadów żywieniowych o spożyciu z ostatnich 24 godzin. Zawartość energii, białka, tłuszczu i węglowodanów oraz wybranych składników mineralnych (potas, wapń, fosfor, magnez, żelazo, cynk, miedź) i witamin (A, E, B₁, B₂, B₆, B₁₂, PP i C) w spożywanej diecie obliczono w oparciu o aktualne „Tabele składu i wartości odżywczej żywności”, natomiast ilości suplementowanych składników odżywczych na podstawie składu deklarowanego przez producentów odżywek. Otrzymane wyniki dotyczące spożycia składników odżywczych z dietą oraz łącznie z suplementami odniesiono do aktualnych norm żywienia człowieka na poziomie średniego zapotrzebowania grupy (EAR) oraz zaleceń dla sportowców. Wyniki badań wykazały niedostateczne spożycie energii, białka i węglowodanów, które wynosiło odpowiednio 80,3%; 83,0% i 60,4% zaleceń oraz niewłaściwe proporcje składników dostarczających energii w diecie. Suplementacja odżywkami była celowa w tym zakresie, gdyż uzupełniła energię i brakujące składniki oraz przywróciła właściwe proporcje białka, tłuszczów i węglowodanów w dostarczaniu energii. Spożywana przez zawodników dieta (bez odżywek) zawierała odpowiednią, w stosunku do zaleceń, ilość witamin i składników mineralnych, z wyjątkiem potasu, dlatego dodatkowe ich spożycie z odżywkami było nieuzasadnione, a w przypadku magnezu przekroczyło górny tolerowany poziom spożycia (UL).The aim of this study was to assess the usefulness of administering food supplements to male weightlifters (n = 13), members of the Polish National team, while on a training camp. The intakes of energy, protein, fat, carbohydrates, selected minerals (Ca, P, Mg, Fe, K, Zn, Cu) and vitamins (A, C, E, B₁, B₂, B₆, B₁₂ and niacin) were assessed from 24 h dietary recalls for the preceding day. The data concerning energy and selected nutrients in the diets was calculated from the current “Food Composition Tables” and in case of food supplements - from compositions declared by manufacturers; these were related to the official Polish norms of the estimated average requirements (EAR) and special recommendations for athletes. The results of the study indicated insufficient intakes of energy, proteins and carbohydrates (80,3; 83,0 and 60,4%, respectively) and inadequate proportions of macronutrient energy sources. The administered food supplements compensated for insufficient supplies of energy and food components and for inappropriate proportions of energy sources. The intakes of selected vitamins and minerals in diets without supplementation were adequate, for with the exception of potassium. Thus, the application of food supplements proved to be unnecessary except for the latter component. In case of magnesium supplementation exceed tolerable upper intake level (UL)

THE ROLE OF SALIVARY IMMUNOGLOBULIN A IN THE PREVENTION OF THE UPPER RESPIRATORY TRACT INFECTIONS IN ATHLETES – AN OVERVIEW

Athletes subjected to high work loads may experience temporary suppression of the functions in the immune system which increases the susceptibility to infections of such subjects. Namely, upper respiratory tract infections (URTI) are the most common disorders among individuals subjected to high work loads and that issue is of utmost importance for sport immunologists. So far, no simple explanation has been offered as to the specific roles of detailed elements of the immune system in URTI incidence. One of the most likely markers is supposed to be the secretory immunoglobulin A (sIgA), associated with mucosal membranes of upper respiratory  tracts, although the results are far from being unequivocal yet. The most important results published in that area were discussed in this paper

The effect of body size and composition on lumbar spine trabecular bone score in morphologically diverse subjects.

AimThe trabecular bone score (TBS) is a tool for assessing bone quality and health. Current TBS algorithm corrects for body mass index (BMI), as a proxy of regional tissue thickness. However, this approach fails to consider BMI inaccuracies due to individual differences in body stature, composition and somatotype. This study investigated the relationship between TBS and body size and composition in subjects with a normal BMI, but with large morphological diversity in body fatness and height.MethodsYoung male subjects (n = 97; age 17.2±1.0 years), including ski jumpers (n = 25), volleyball players (n = 48) and non-athletes (controls n = 39), were recruited. The TBS was determined from L1-L4 dual-energy X-ray absorptiometry (DXA) scans using TBSiNsight software.ResultsTBS correlated negatively with height and tissue thickness in the L1-L4 area in ski jumpers (r = -0.516 and r = -0.529), volleyball players (r = -0.525 and r = -0.436), and the total group (r = -0.559 and r = -0.463), respectively. Multiple regression analyses revealed that height, L1-L4 soft tissue thickness, fat mass and muscle mass were significant determinants of TBS (R2 = 0.587, pConclusionThe negative association of TBS and both features suggests that a very low L1-L4 tissue thickness may lead to overestimation of the TBS, while tall stature may have the opposite effect. It seems that the utility of the TBS as a skeletal assessment tool in lean and/or tall young male subjects could be improved if tissues thickness in the lumbar spine area and stature instead of BMI were considered in the algorithm