Association Between Vitamin D Status and Testosterone and Cortisol in Ice Hockey Players

The identification of the vitamin D receptor in tissues related to testosterone and cortisol production, in conjunction with the observed correlations between vitamin D levels and these hormones in the general population, suggest vitamin D may influence testosterone and cortisol concentrations in athletes. A crosssectional study design was used to evaluate the association between 25(OH)D and testosterone and cortisol concentrations in young male ice hockey players (n = 50). All athletes were recruited during October from the Sosnowiec area, Poland (50° N). Commercially available ELISA kits were used to determine total serum 25(OH)D, testosterone and cortisol concentrations. Serum 25(OH)D concentration was analyzed as both a continuous and dichotomous variable, binned at the criteria for deficiency (\u3c 20 ng·ml-1), to investigate a threshold effect. Neither continuous (r = 0.18, p = 0.20) nor dichotomous (r = 0.16, p = 0.27) 25(OH)D concentration was significantly correlated with testosterone concentration. A small, inverse correlation (r = -0.30, p = 0.04) was detected between 25(OH)D and cortisol concentrations when analyzed as a dichotomous variable only. Serum 25(OH)D concentration was neither associated with testosterone (p = 0.09) nor cortisol concentrations (p = 0.11) after adjusting for age, fat free mass and fat mass in sequential linear regression. The inability of vitamin D status to independently predict testosterone and cortisol concentrations suggests that any performanceenhancing effects of vitamin D in athletes are unlikely to be mediated primarily through these hormones, at least amongst young male ice-hockey players

Association Between Vitamin D Status and Testosterone and Cortisol in Ice Hockey Players

The identification of the vitamin D receptor in tissues related to testosterone and cortisol production, in conjunction with the observed correlations between vitamin D levels and these hormones in the general population, suggest vitamin D may influence testosterone and cortisol concentrations in athletes. A crosssectional study design was used to evaluate the association between 25(OH)D and testosterone and cortisol concentrations in young male ice hockey players (n = 50). All athletes were recruited during October from the Sosnowiec area, Poland (50° N). Commercially available ELISA kits were used to determine total serum 25(OH)D, testosterone and cortisol concentrations. Serum 25(OH)D concentration was analyzed as both a continuous and dichotomous variable, binned at the criteria for deficiency (\u3c 20 ng·ml-1), to investigate a threshold effect. Neither continuous (r = 0.18, p = 0.20) nor dichotomous (r = 0.16, p = 0.27) 25(OH)D concentration was significantly correlated with testosterone concentration. A small, inverse correlation (r = -0.30, p = 0.04) was detected between 25(OH)D and cortisol concentrations when analyzed as a dichotomous variable only. Serum 25(OH)D concentration was neither associated with testosterone (p = 0.09) nor cortisol concentrations (p = 0.11) after adjusting for age, fat free mass and fat mass in sequential linear regression. The inability of vitamin D status to independently predict testosterone and cortisol concentrations suggests that any performanceenhancing effects of vitamin D in athletes are unlikely to be mediated primarily through these hormones, at least amongst young male ice-hockey players

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

Exercise Training-Induced Changes in Inflammatory Mediators and Heat Shock Proteins in Canoeists

According to cytokine overtraining theory, skeletal muscle injuries are related to systemic inflammatory reaction. In response to inflammation, cells rapidly produce a series of proteins known as heat shock proteins (HSPs).These are considered to be molecular chaperones which play a universal role in maintaining cellular homeostasis. Among the subset of stress-responsive proteins, HSP27 and HSP70 are considered to be a new approach to monitoring exercise training and adaptive mechanisms. The study was designed to demonstrate the effect of sport training on changes in pro-inflammatory cytokines and HSPs, and their relation with muscle damage and body composition. Six elite canoeists (19.8 ±2.9 yr) were observed during preparatory training period (March) at the 1st, the 4th and after 7 days of the conditioning camp, and then after 3 days of recovery. The canoeing training did not induce muscle damage, decreased in IL-1β and HSP27, increased in TNFα and HSP70 concentrations. The highest changes in TNFα and HSP70 were observed 3 days after conditioning camp (during recovery) compared to initial level (the 1st day of conditioning camp). TNFα correlated with HSP27 (r = –0.563; P < 0.01) and HSP70 (r = 0.651; P < 0.001). Any significant changes in body composition were not observed. In conclusion, we could say that typical canoeing training improves cytokines and HSPs release, however, the changes are not related to muscle damage

Echocardiographic evaluation of cardiovascular system in adolescent athletes in view of physiological adaptation to physical training

Wstęp. Ocena układu krążenia u młodych sportowców pozostaje tematem aktywnych badań. Duże trudności pojawiają się w zakresie oceny wielkości i grubości jam serca ze względu na istotne różnice antropometryczne między poszczególnymi zawodnikami gdzie trening fizyczny (nierzadko bardzo intensywny) nakłada się na okres dojrzewania i szybkiego wzrostu. Celem pracy była ocena wpływu regularnego wysiłku fizycznego na układ krążenia u dorastających sportowców. Materiał i metody. W badaniu oceniano 89 sportowców — 41 jeden piłkarzy oraz tenisistów (grupa 1.) oraz 48 rozpoczynających karierę sportową wioślarzy (grupa 2.). U wszystkich kwalifikujących się zawodników wykonano badanie ergospirometryczne z oceną szczytowego pochłaniania tlenu (VO2max) oraz badania elektrokardiograficzne i echokardiograficzne. Wyniki. Porównano sportowców z obu grup, tj. piłkarzy i tenisistów (grupa 1.) z grupą wioślarzy (grupa 2.). Obie grupy nie różniły się wiekiem (14,2 ± 1,1 v. 14,3 ± 1,2 roku; p = NS) oraz płcią (dziewczęta: 6 [7,6%] v. 8 [10,2%]; p = NS]. Dłużej trenujący piłkarze i tenisiści, w porównaniu z grupą wioślarzy, różnili się pod względem parametrów antropometrycznych, parametrów wydolności fizycznej oraz spoczynkowej częstości rytmu serca. Większość wymiarów jam serca indeksowanych względem pola powierzchni ciała była większa w grupie osób dłużej trenujących piłkarzy i tenisistów (końcoworozkurczowy wymiar lewej komory: 29,1 ± 2,5 v. 26,8 ± 2,7 mm/m2; p < 0,001; grubość przegrody międzykomorowej: 6,0 ± 0,7 v. 5,4 ± 0,8 mm; p = 0,001; grubość ściany tylnej: 0,8 ± 0,6 v. 5,2 ± 0,6; p < 0,001; proksymalny fragment drogi odpływu prawej komory: 16,1 ± 2,2 v. 14,5 ± 2,0 mm/m2; p = 0,001; wymiar drogi napływu prawej komory: 19,9 ± 2,1 v. 18,5 ± 2,6 mm/m2; p = 0,01). Po zastosowaniu indeksacji allometrycznej większość oberwanych różnic przestała mieć znaczenie istotne statystycznie, z wyjątkiem indeksowanej masy lewej komory (87,0 ± 13,9 v. 76,8 ± 12,2 g/(m2)1,5; p = 0,001). Wnioski. 1. Zastosowanie indeksacji allometrycznej w stosunku do parametrów echokardiograficznych u dorastających sportowców wydaje się właściwe ze względu na nieliniową zależność pomiędzy tempem wzrostu, a szybkością zwiększania się narządów wewnętrznych w tej grupie wiekowej. 2. Nawet krótki trening fizyczny u dorastających sportowców ma istotny wpływ na poprawę parametrów wydolności fizycznej, bez znaczącego wpływu na większość parametrów morfologicznych serca.Introduction. Assessment of cardiovascular system in young athletes is a subject of active research. Cardiac morphology is difficult to evaluate due to significant anthropometric differences between individuals, especially during puberty and growth spurt. The aim of this paper was an assessment of systematic physical training’s impact on cardiovascular system and cardiac remodeling in young athletes. Material and methods. Study involved 89 adolescent athletes, including 41 football players and tennis players (group 1) and 48 beginner rowers (group 2). All athletes included in the study underwent ergospirometric tests with evaluation of peak oxygen uptake (VO2max) as well as a 12-lead electrocardiographic and echocardiographic evaluation. Results. Athletes in group 1 (football/tennis players) were compared to group 2 (rowers). There were no significant differences in age (14.2 ± 1.1 vs. 14.3 ± 1.2 years, p = NS) or sex (6 [7.6%] vs. 8 women [10.2%], respectively, p = NS). Differences were observed in anthropometric parameters, cardiopulmonary fitness, and resting heart rate. Most parameters of cardiac morphology indexed to body area (indexed value: raw data/bodu surface area) were greater in group 1 (left ventricular end-diastolic dimension 29.1 ± 2.5 vs. 26.8 ± 2.7 mm/m2, p < 0.001; septal thickness: 6.0 ± 0.7 vs. 5.4 ± 0.8 mm, p = 0.001; posterior wall thickness: 0.8 ± 0.6 vs. 5.2 ± 0.6, p < 0.001; proximal part of right ventricle outflow tract: 16.1 ± 2.2 vs. 14.5 ± 2.0 mm/m2, p = 0.001; right ventricle inflow tract: 19.9 ± 2.1 vs. 18.5 ± 2.6 mm/m2, p = 0.01). When allometric scaling was employed, most differences were insignificant, apart from indexed left ventricle mass (87.0 ± 13.9 vs. 76.8 ± 12.2 g/(m2)1.5, p = 0.001). Conclusions. 1. Allometric indexation of echocardiographic parameters in young athletes is appropriate since relationship between body height increase and the rate of internal organ growth in these subjects is non-linear. 2. Even a short physical training in young athletes has impact on their condition but does not significantly affect parameters of cardiac morphology

Air gaps under the clothing-measurement and impact on the thermal insulation of the clothing

Wymiana ciepła w układzie odzież - źródło ciepła zależy w dużej mierze od izolacyjności cieplnej odzieży. Jest to podstawowy parametr opisujący użyty zestaw odzieży, na który składa się opór cieplny poszczególnych warstw odzieży. Uwzględnia on także występujące pomiędzy warstwami pustki powietrza, których występowanie związane jest ze stopniem dopasowania odzieży do sylwetki użytkownika. Rozmiar powstałych pustek powietrza może być analizowany za pomocą technik skanowania 3D. W artykule przedstawiono problem występowania pustek powietrza (a więc pośrednio stopnia dopasowania odzieży do sylwetki) i ich znaczenie.Heat transfer in the clothing - heat source system depends largely on the thermal insulation of the clothing. This is the basic parameter describing the set of clothing used, which consists of the thermal resistance of the individual layers of clothing. It also takes in to account the air gaps between the layers. The occurrence of the air gaps is related to the degree of fitting the garment to the user's body shape The size of the air gaps formed can be analyzed using 3D scanning techniques. The article presents the problem of the occurrence of air gaps (and thus indirectly the degree of fitting the garment to the body shape) and their significance

Differences between anthropometric indicators and the impact force of taekwondo kicks performed with the dominant and non-dominant limb

Study aim: Taekwondo is known for its very dynamic sports fighting, in which the athletes perform strikes mainly with their lower limbs. The aim of the study was to compare the differences between the impact force of strikes performed with the dominant and non-dominant limbs and its correlation with anthropometric indicators

Hydration Status in Men Working in Different Thermal Environments: A Pilot Study

The aim of this study was to determine the effects of different seasons of the year and the time of day (before work vs. after work) on hydration status in men. The study involved sixty foresters who spent most of the work outdoors. During three seasons of the year (summer, autumn, and winter), indices of hydration status (body mass (BM) and percentage change of BM, total body water (TBW) and percentage change of TBW, serum osmolality (Sosm) and percentage change of Sosm, urine osmolality, urine-specific gravity (USG), urine color, and thirst) were determined before work on the first day (time point 1 used as baseline), immediately after work on the first day (time point 2), and before work on the following day (time point 3). USG decreased at time point 2 compared to time point 1 (p < 0.001) and time point 3 (p = 0.03). At time point 2 (p = 0.002) in winter and time point 3 in autumn (p = 0.049), serum osmolality was higher than in summer. In conclusion, the differences in hydration status depended on the time of day and season. A large percentage of foresters come to work inadequately hydrated, especially in colder seasons compared to summer

The impact of exposure to cold on manual skills of a worker using protective gloves

Ekspozycja na środowisko zimne może negatywnie wpływać na organizm pracownika. Niekorzystne warunki mogą prowadzić do wychłodzenia części dystalnych, jak również organizmu, a nawet do hipotermii. W artykule skupiono uwagę na jednym z elementów wpływu środowiska zimnego na organizm człowieka, a dokładniej na sprawności manualnej. Przedstawiono w nim wpływ środowiska zimnego na zmiany sprawności rąk, co z kolei może się przekładać m.in. na zwiększenie liczby wypadków, a więc bezpieczeństwo pracy.Exposure to a cold environment may have a negative effect on the worker's body. Unfavorable conditions can lead to the cooling of the distal parts as well as the body, and even to hypothermia. The following article focuses on one of the elements of the influence of the cold environment on the human body – on manual skills. It presents the influence of the cold environment on changes in hand dexterity, which in turn may translate into e.g. to increase the number of accidents, and therefore work safety