Impact of the COVID-19 pandemic on competitive swimming performance

OBJECTIVE This article aims to conduct a comparison of swimming performance during short course national championships (25-m) from 2019 and 2020 (before and during the pandemic). MATERIALS AND METHODS The data points from the championships will be compared for 5 European countries: Poland, Spain, Russia, Turkey, and Denmark. Times achieved in the finals were calculated by the analysis of variance. Post hoc pairwise comparison analysis was performed using Tukey's test. The analysis plan included the assessment of the main effects and the effect of interactions in the groups of women and men. The strength of the effect was expressed by the partial eta-squared ratio. RESULTS Two main trends were observed in the results. The first was a greater variation in the results in the group of men than in women (12-5 differences). The second was the development and improvement of sports performance in symmetrical strokes (69% improvement in recorded times measured during the pandemic, e.g., in Poland, women on 50-m breaststroke and butterfly Δ = 0.52, p <0.001 and Δ = 0.32, p = 0.034, men on 50-m and 100-m butterfly Δ = 0.34, p = 0.003 and Δ = 1.21, p <0.001). CONCLUSIONS The main conclusion of our analysis is that the pandemic influenced the development of sports performance in symmetrical techniques, i.e., in breaststroke and butterfly

Combined carbon content assessment method for powder metallurgy

Purpose Powder metallurgy (PM) lacks a clear method to analyse the combined carbon content based on metallography visualisation, and this article describes the creation of such a method for powder materials. Design/methodology/approach Different methods are used to analyse combined carbon within metallurgical samples, and the hardness of components within the automotive industry is related to this question. Findings The main aim of this paper is to determine if optical microscopy provides a reliable means to assess the combined carbon content. Research limitations/implications For checking these items, the Optical Microscope will be used, density, hardness of sinter material, and particle size laser analysis of powder for creating the observed compact, and SEM microscope. Practical implications This investigation provides standardised rules that can be implemented within any material laboratory. Originality/value The analysis of powder particle size, hardness test, density check, and the investigation of the structure of powder element are presented

THE ROLE OF AEROBIC CAPACITY IN HIGH-INTENSITY INTERMITTENT EFFORTS IN ICE-HOCKEY

The primary objective of this study was to determine a relationship between aerobic capacity ( ·VO2max) and fatigue from high-intensity skating in elite male hockey players. The subjects were twenty-four male members of the senior national ice hockey team of Poland who played the position of forward or defence. Each subject completed an on-ice Repeated-Skate Sprint test (RSS) consisting of 6 timed 89-m sprints, with 30 s of rest between subsequent efforts, and an incremental test on a cycle ergometer in the laboratory, the aim of which was to establish their maximal oxygen uptake ( ·VO2max). The analysis of variance showed that each next repetition in the 6x89 m test was significantly longer than the previous one (F5,138=53.33, p<0.001). An analysis of the fatigue index (FI) calculated from the times recorded for subsequent repetitions showed that the value of the FI increased with subsequent repetitions, reaching its maximum between repetitions 5 and 6 (3.10±1.16%). The total FI was 13.77±1.74%. The coefficient of correlation between ·VO2max and the total FI for 6 sprints on the distance of 89 m (r =–0.584) was significant (p=0.003). The variance in the index of players’ fatigue in the 6x89 m test accounted for 34% of the variance in ·VO2max. The 6x89 m test proposed in this study offers a high test-retest correlation coefficient (r=0.78). Even though the test is criticized for being too exhaustive and thereby for producing highly variable results it still seems that it was well selected for repeated sprint ability testing in hockey players

Effects of hypoxia during continuous and intermittent exercise on glycemic control and selected markers of vascular function in Type I Diabetics

Objectives : The aim of the study was to assess the effect of continuous and intermittent exercise in hypoxia on glycaemic control and selected markers of vascular function in patients with Type 1 diabetes (T1D). Methods : 12 patients suffering from T1D for 12.1±6.0 years and 12 healthy adults performed: continuous exercise (ExC) and intermittent exercise (ExInt) in normoxia and hypoxia (FiO₂=15.1%). Glycaemia and proangiogenic factors concentrations were measured at rest and immediately after exercise. Results : T1D patients' glycaemia decreased in response to ExC (p<0.01) and ExInt (p<0.05) under hypoxic conditions. ExInt in normoxia (p<0.05) and hypoxia (p<0.05) reduced HIF-1α in the T1D group. A tendency for vascular endothelial growth factor to increase after ExInt in hypoxia (6.0±3.8 vs. 17.1±13.07 pg/mL) and a proinflammatory cytokine TNF-α level to decrease (33.2±19.1 vs. 25.1±14.4 pg/mL) was found in the same group. Conclusions : Combining exercise with hypoxia may allow more effective short-term glycaemic control in T1D. Intermittent exercise with hypoxia could stabilize the secretion of selected proangiogenic factors and reduce inflammation, potentially leading to improved vascular function

Стартова фобія та рівень оптимізму у дітей, які практикують спортивне обладнання

Мета дослідження полягає в тому, щоби показати залежність між переживанням стартової фобії та почуттям оптимізму у дітей, які займаються спортивним плаванням, і перевірити взаємозв'язок між віком обстежуваних і їх статтю. Для вивчення використано Тест мобілізації передстартової та Опитувальник стилю атрибуції. У дослідженні приймали участь 23 плавці у віці від 13 до 14 років (14 дівчат та 9 хлопчиків), які практикували спортивне плавання в клубі УКС Zabiaka в Гданську. Дослідження, проведені під час початку змагань з плавання в рамках Ліги Поморського регіону. Анкети були заповнені кожним з учасників безпосередньо перед стартом. Результати дослідження показують, що існує кореляція між переживанням стартової фобії та оптимізмом, також віком і статтю респондентів. Підтверджено, що плавці, які слідували оптимістичному стилю атрибуції, більше переживали стартові фобії, а хлопчики менше відчували стартові фобії, ніж дівчатка. З віком знижується рівень відчуття стартової фобії. Крім того, дівчатка мають більш оптимістичний стиль атрибуції, ніж хлопчики, а також з віком обстежуваних зростає рівень оптимізму

ОЗДОРОВЧІ ВЛАСТИВОСТІ РУХОВОЇ ПОВЕДІНКИ НА ПРИКЛАДІ СКАНДИНАВСЬКОЇ ХОДЬБИ ТА МЕТАБОЛІЗМУ ЗАЛІЗА

Вважається, що рухова поведінка людини впливає на її здоров’я та покращує фізичну форму, покращує загальні хімічні реакції та пов’язані з ними енергетичні зміни, які відбуваються в живих клітинах, генеруючи дослідницькі виклики для багатьох галузей науки. Зацікавленість авторів збуджує зростаючий рух скандинавської ходьби як системи масових подій і її позитивний вплив на метаболізм заліза в організмі людини

Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams

The purpose of this study was to examine physiological and physical determinants of ice-hockey performance in order to assess their impact on the result during a selection for ice hockey. A total of 42 ice hockey players took part in the selection camp. At the end of the camp 20 best players were selected by team of expert coaches to the ice hockey team and created group G1, while the second group (G2) consisted of not selected players (non-successful group Evaluation of goodness of fit of the model to the data was based on the Hosmer Lemeshow test Ice hockey players selected to the team were taller 181.95±4.02 cm, had lower % body fat 13.17±3.17%, a shorter time to peak power 2.47±0.35 s , higher relative peak power 21.34±2.41 W • kg-1 and higher relative total work 305.18±28.41 J • kg-1. The results of the aerobic capacity test showed significant differences only in case of two variables. Ice hockey players in the G1 had higher VO2max 4.07±0.31 l • min-1 values than players in the G2 as well as ice hockey players in G1 showed a higher level of relative VO2max 51.75±2.99 ml • min-1 • kg-1 than athletes in G2. Ice hockey players selected to the team (G1) performed better in the 30 m Forwards Sprint 4.28±0.31 s; 6x9 Turns 12.19±0.75 s; 6x9 stops 12.79±0.49 s and Endurance test (6x30 m stops) 32.01±0.80 s than players in G2. The logistic regression model showed that the best predictors of success in the recruitment process of top level ice hockey players were time to peak power, relative peak power, VO2max and 30 m sprint forwards on ice. On the basis of the constructed predictive logistic regression model it will be possible to determine the probability of success of the athletes during following the selection processes to the team

Coordination and propulsion and non-propulsion phases in 100 meters breaststroke swimming

Purpose: The main purpose of this study to analyze the coordination, propulsion and non-propulsion phases in the 100 meters breaststroke race. Methods: Twenty-seven male swimmers (15.7±1.98 years old) with the total body length (TBL) of 247.0±10.60 [cm] performed an all-out 100m breaststroke bout. The bouts were recorded with an underwater camera installed on a portable trolley. The swimming kinematic parameters, stroke rate (SR) and stroke length (SL), as well as the coordination indices based on propulsive or non-propulsive movement phases of the arms and legs were distinguished. Results: Swimming speed (V 100surface breast ) was associated with SL (R=0.41, p<0.05) and with TBL tending towards statistical significance (R=0.36, p<0.07), all relationships between the selected variables in the study were measured using partial correlations with controlled age. SL interplayed negatively with the limbs propulsive phase Overlap indicator (R=-0.46, p<0.05), but has no significant relationship to the non-propulsion Glide indicator. Conclusions: The propulsion in-sweep (AP3) phase of arms and their non-propulsion partial air recovery (ARair) phase interplayed with V 100surface breast (R=0.51, p<0.05 and 0.48 p<0.05) respectively, displaying the importance of proper execution of this phase (AP3) and in reducing the resistance recovery phases in consecutive ones

ПОШКОДЖЕННЯ ПІД ЧАС СПОРТИВНОГО ПЛАВАННЯ ТА ЇХ РЕАБІЛІТАЦІЯ

Ця стаття містить дані, пов’язані з плаванням, реабілітацією в спорті, лікуванням травм та запобіганням неналежному тренінгу. Питання, що є частиною цієї дисципліни, представлені та обговорюються. Плавання та реабілітація тісно пов’язані один з одним через часте перевантаження, пошкодження та травми, викликані тренуванням або неправильним вибором обладнання