Wyniki wyszukiwania - Biblioteka Nauki

1

HIGH INTENSITY STRENGTH TRAINING IN OVERWEIGHT ADULTS IN THE WORKPLACE: A PILOT STUDY

100%

Borràs P. A. , Vidal-Conti J. , Palou P.

Journal of Physical Education & Health - Social Perspective

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2016

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tom 5

|

nr 7

35-42

XX

The aim of this pilot study was to determine (a) the effects of high intensity strength training in the workplace on blood pressure, fat percentage and physical fitness in overweight adults, and (b) the influence of this intervention on the blood pressure in a subsample of hypertensive subjects. Overweight adults (n=15) aged 42.8 years underwent anthropometric assessment (weight, fat percentage, waist circumference, and triceps skinfold), physical fitness assessment (leg extensor power, upper body endurance, hand grip strength and Vo2max) and blood pressure assessment before and after 8 weeks of high intensity resistance training in the workplace. Each training session consisted of 16 sets of 45 repetitions performed at 1 repetition per second, decreasing load at the point of muscular failure starting at 60% of repetition maximum (RM). The effects of the intervention were analyzed by paired sample t-tests. For exploratory purposes, a non-parametric test was also performed (Wilcoxon matched-pair signed-rank) to examine if this decision could affect the results. Weight, body fat percentage, and triceps skinfold decreased significantly with the high intensity resistance training protocol in the workplace (all P<0.05). Performance in physical fitness tests increased significantly with training (all P<0.05), except for handgrip strength. Both systolic and diastolic blood pressure decreased significantly with R-HIRT in the workplace (all P <0.05) in hypertensive subjects (n=10). This protocol performed in the workplace in this pilot study produces health and fitness benefits in overweight and hypertensive people.

2

Gender’s Effect on a School-Based Intervention in the Prepubertal Growth Spurt

100%

Marta C. , Marinho D. , Casanova N. , Fonseca T. , Vila-Chã C. , Jorge B. , Izquierdo M. , Esteves D. , Marques M.

Journal of Human Kinetics

|

2014

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tom 43

|

nr 1

159-167

EN

Children aged 10-11 years pass through a dynamic developmental period marked by rapid changes in body size, shape, and composition, all of which are sexually dimorphic. The purpose of this study was to analyze the effects of gender on a school-based intervention in the prepubertal growth spurt. One hundred twenty-five healthy children (58 boys, 67 girls), fifth and sixth grade students from an urban public elementary school in Portugal (10.8 ± 0.4 years), were randomly assigned into two experimental groups: a strength training group (19 boys, 22 girls), and an endurance training group (21 boys, 24 girls); and a control group (18 boys, 21 girls; no training program). Training program for the two experimental groups was conducted twice a week for 8 weeks. Compared with the values at the beginning of the protocol, both strength and endurance training programs produced significant improvements (p< 0.05) in vertical and horizontal jumps, a 1 kg and 3 kg medicine ball throw, a 20 m sprint and VO2max, for both boys and girls. No significant changes were observed related to gender in training-induced strength (p> 0.05, ƞ_p^2= 0.16, Power= 0.29) and aerobic (p> 0.05, ƞ_p^2= 0.05, Power= 0.28) capacity. The results of the present study should be taken into consideration in order to optimize strength training school-based programs.

3

The effect of circuit training on physical fitness and archery accuracy in novice athletes

88%

Susanto S. , Siswantoyo S. , Prasetyo Y. , Putranta H.

Physical Activity Review

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2021

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tom 1

|

nr 9

100-108

EN

Introduction: Physical condition is one of the most important factors in supporting archery. the better the physical condition, the better the concentration to support accuracy in archery. Concentration in archery is the ability to target targets accurately. Purpose: The purpose of this study was to determine the effect of circuit training on improving physical fitness and archery accuracy in novice athletes. Materials and Methods: Participants were 20 novice athletes, aged 10 to 12 years. Quasi-experimental research design, using two group pretest-posttest design. The method of collecting data on physical fitness uses the Indonesian physical fitness test (IPFT) aged 10-12 years and the accuracy test is by shooting arrows at the target. Data analysis used paired sample t-test, to determine differences in variable groups of men and women. The analysis results showed no difference if the significant value was less than 0.05 (p<0.05). Before analyzing the data, a prerequisite test was carried out which included the Shapiro Wilk normality test and the variate homogeneity test using the Levene's test. Results: The results showed that there was a significant increase in physical fitness in the male and female groups. Therefore, there was a significant improvement in the accuracy of archery shots in the male and female groups. The study concluded that circuit training is effective for improving physical fitness and archery accuracy in novice athletes.

4

Nordic Walking Training and Physical Fitness in Elderly Women

88%

Ossowski Z. , Prusik K. , Prusik K. , Kortas J. , Wiech M. , Bielawa ł.

Polish Journal of Sport and Tourism

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2015

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tom 21

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nr 4

253-257

EN

Introduction. Together with longer human lives, increase in economy level and higher social expectations, there is also need for developing science studies on physical culture and its role in prevention of ageing. Taking care of physical fitness is one of the main factor that guarantees both health and high quality life for millions of older people. The purpose of this article was to determine the changes of physical fitness level under the influence of Nordic walking trainingin women aged 60-75 years. Material and methods. 65 women aged 60-75 years were the subject of this study. Women were divided into 2 groups: control group (26 people) and experimental group (39 people). Women from experimental group were taking part in Nordic walking training for 15 weeks, 2 times a week, 60 minutes each meeting. To determine the level of physical fitness some trials from EUROFIT test for adults were applied and march test 2 km was held. Results. The trend of improvement of physical fitness under health education and Nordic walking training was determined. The best results was on endurance field (statistically significant p<0.05). It was also observed slight decrease in physical fitness in women that didn't take part in mentioned training.

5

Comparision of power changes in rebound and fast run versus time for 11 year-old boys being in and out of training

88%

Urbanik C. , Milewska-Moneta L.

|

1999

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tom Vol. 1, nr 1

89-94

EN

The purpose of this study was to compare the changes in power and speed of running versus time for 11 year-old boys training (n-17) endurance competitions and being out of training (n-17). The estimate bases were the changing speed of power on an inclined plane and the change of speed for 400 m run in 25 m sections. In both tests each effort required maximal intensity. During the experimental period very similar characters of speed and power changes versus time were obtained for both tested groups and the differences are due to the training degree.

6

Endurance and Speed Capacity of the Korea Republic Football National Team During the World Cup of 2010

88%

Duk O. , Min K. , Kawczyński A. , Chmura P. , Mroczek D. , Chmura J.

Journal of Human Kinetics

|

2011

|

tom 30

115-121

EN

The aim of the study was to characterize selected indices of endurance and speed of the Korea Republic team with reference to the four best teams during the World Cup of 2010. Five hundred and ninety-nine football players from thirty-two teams participated in the study. All teams played in the 2010 World Cup in South Africa. For the assessment of the players' motor activity during matches common kinematic test results were recorded using the Castrol Performance Index. The following variables were analysed: total distance covered by the team, distance covered by individual players, maximum running speed and average match running speed for the team and individual players, as well as with division with regard to playing position: defenders, midfielders, strikers. In comparison to the four best teams at the football World Cup of 2010, the Korea Republic players achieved the highest running speed (p≤0.05), and similar levels of covered distance and average match running speed.

7

Serum Concentrations of S100B are not Affected by Cycling to Exhaustion With or Without Vibration

88%

Schulte S. , Schiffer T. , Sperlich B. , Kleinöder H. , Holmberg H.

Journal of Human Kinetics

|

2011

|

tom 30

59-63

EN

The calcium-binding protein S100B is produced primarily by astrocytes and exerts concentration-dependent paracrine and autocrine effects on neurons and glia. The numerous findings of a correlation between S100B and traumatic brain injury (TBI) have resulted in the employment of this protein as a clinical biomarker for such injury. Our present aim was to determine whether cycling with (V) or without (NV) vibration alters serum concentrations of S100B. Twelve healthy, male non-smokers (age: 25.3±1.6 yrs, body mass: 74.2±5.9 kg, body height: 181.0±3.7 cm, VO2peak: 56.9±5.1 ml·min-1·kg-1 (means ± SD)) completed in random order two separate trials to exhaustion on a vibrating bicycle (amplitude 4 mm and frequency 20 Hz) connected to an ergometer. The initial workload of 100 W was elevated by 50 W every 5 min and the mean maximal period of exercise was 25:27±1:30 min. The S100B in venous blood taken at rest, immediately after the test, and 30, 60 and 240 min post-exercise exhibited no significant differences (p>0.05), suggesting that cycling with and without vibration does not influence this parameter.

8

Measurement of Cardiorespiratory Fitness in Children from Two Commonly Used Field Tests After Accounting for Body Fatness and Maturity

88%

Hamlin M. J. , Fraser M. , Lizamore C. A. , Draper N. , Shearman J. P. , Kimber N. E.

Journal of Human Kinetics

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2014

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tom 40

|

nr 1

83-92

EN

Body fat and maturation both influence cardiorespiratory fitness, however few studies have taken these variables into account when using field tests to predict children’s fitness levels. The purpose of this study was to determine the relationship between two field tests of cardiorespiratory fitness (20 m Maximal Multistage Shuttle Run [20-MST], 550 m distance run [550-m]) and direct measurement of VO2max after adjustment for body fatness and maturity levels. Fifty-three participants (25 boys, 28 girls, age 10.6 ± 1.2 y, mean ± SD) had their body fat levels estimated using bioelectrical impedance (16.6% ± 6.0% and 20.0% ± 5.8% for boys and girls, respectively). Participants performed in random order, the 20-MST and 550-m run followed by a progressive treadmill test to exhaustion during which gas exchange measures were taken. Pearson correlation coefficient analysis revealed that the participants’ performance in the 20-MST and 550-m run were highly correlated to VO2max obtained during the treadmill test to exhaustion (r = 0.70 and 0.59 for 20-MST and 550-m run, respectively). Adjusting for body fatness and maturity levels in a multivariate regression analysis increased the associations between the field tests and VO2max (r = 0.73 for 20-MST and 0.65 for 550-m). We may conclude that both the 20-MST and the 550-m distance run are valid field tests of cardiorespiratory fitness in New Zealand 8-13 year old children and incorporating body fatness and maturity levels explains an additional 5-7% of the variance.

9

Effects of Elbow Flexor Muscle Resistance Training on Strength, Endurance and Perceived Exertion

88%

Gonçalves M. , Souza Castelo Oliveira A.

Human Movement

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2013

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tom 14

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nr 2

110-115

EN

Purpose. To verify the effects of resistance training at the electromyographic fatigue threshold (EMGFT) based on one-repetition maximum strength (1RM), heart rate (HR), rate of perceived exertion (PE) and endurance time (EndT). Methods. Nineteen subjects (training group [TG]: n = 10; control group [CG]: n = 9), performed 1-min bicep curl exercises sets at 25%, 30%, 35% and 40% 1RM. Electromyography (biceps brachii and brachiorradialis), HR and PE were registered. Biceps brachii EMGFT was used to create a load index for an eight-week resistance training programme (three sets until exhaustion/session, two sessions/week) for the TG. The CG only attended one session in the first week and another session in the last week of the eight-week training period for EndT measurement. EndT was determined from the number of repetitions of each of the three sets performed in the first and last training sessions. After training, 1RM, EMGFT, EndT, HR and PE at the different bicep curl load intensities were again measured for both groups. Results. Increases in 1RM (5.9%, p < 0.05) and EndT (> 60%, p < 0.001) after training were found. In addition, PE was reduced at all load intensities (p < 0.05), while no changes were found for HR and EMGFT after training. Conclusions. Strength-endurance training based on the EMGFT improved muscular endurance and also, to a lesser extent, muscular strength. Moreover, the reduced levels of physical exertion after training at the same intensity suggest that endurance training exercises may improve comfort while performing strength exercises.

10

Improving Flexibility and Endurance of Elderly Women Through a Six-Month Training Programme

88%

Plachy J. , Kovách M. , Bognár J.

Human Movement

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2012

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tom 13

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nr 1

22-27

EN

Purpose. Advancing age is associated with predictable sensory, motor and cognitive changes, which may have a potential impact on an older person's ability to function effectively in society. The purpose of this study was to assess whether two slightly different half-year-long regular training programmes had a positive effect on flexibility, range of motion and endurance in a sample population of elderly persons. Also analysed was which programme was found to be more effective. Methods. A group of women (N = 42, M = 67.1 ± 4.5 years) was chosen from retired persons clubs from Eger, Hungary. They were randomly divided into three groups. The first group (N = 15, M = 66.2 ± 3.8 years) took part in a one-hour-long Pilates training session three times a week, the second group (N = 15, M = 67.1 ± 5.9 years) took part in an aqua-fitness class twice a week with one Pilates class once a week and the third group (N = 12, M = 68.2 ± 3.2 years) was the control group. Pre-and postmeasurements were conducted on: flexion of the right shoulder and hip, lumbar spine flexion, thoracolumbar spine flexion, trunk lateral flexion on the right side, a 6-minute walk test, and a 30-second sit-to-stand test. Significant inter-group differences could be found in all of the measurements. Data were analysed using statistical software with the Paired-Samples T-test and Multivariate Analysis of Variance (p < 0.05). Results. After the six-month regular training programmes no differences were found in the control group. For the two groups subjected to the training programmes all the other variables showed significant differences. The most remarkable results for the Pilates group were with the 6-minute walk and sit-to-stand test, while for the aqua-fitness and Pilates group shoulder and hip flexion. Conclusions. A half-year-long training program can considerably improve the physical performance elderly adults need in everyday life.

11

Questioning the Resistance/Aerobic Training Dichotomy: A Commentary on Physiological Adaptations Determined by Effort Rather than Exercise Modality

75%

Fisher J. , Steele J.

Journal of Human Kinetics

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2014

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tom 44

|

nr 1

137-142

EN

This paper discusses and challenges the current opinion that exercise adaptation is generally defined by modality; resistance exercise (RE), or aerobic exercise (AE). In presenting a strong body of recent research which demonstrably challenges these perceptions we suggest alternate hypotheses towards physiological adaptation which is hinged more upon the effort than the exercise modality. Practical implications of this interpretation of exercise adaptation might effect change in exercise adherence since existing barriers to exercise of time, costs, specialized equipment, etc. become nullified. In presenting the evidence herein we suggest that lay persons wishing to attain the health and fitness (including strength and muscle hypertrophy) benefits of exercise can choose from a wide range of potential exercise modalities so long as the effort is high. Future research should consider this hypothesis by directly comparing RE and AE for acute responses and chronic adaptations.

12

RELATIONSHIPS BETWEEN PHYSICAL CHARACTERISTICS AND RANKING OF YOUNG TENNIS PLAYERS

75%

Meckel Y. , Hophy A. , Dunsky A. , Eliakim A.

Central European Journal of Sport Sciences and Medicine

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2015

|

tom 10

|

nr 2

5-12

EN

The purpose of the present study was: 1) to determine young tennis players’ fitness and anthropometric characteristics; and 2) to determine to what extent these characteristics relate to the players’ national ranking. Forty young (age 15.1 ±0.4) trained male tennis players, who were ranked from 1 to 40 in their age group in the country’s youth tennis players list, were tested for speed, speed endurance, flexibility, strength, specific agility and quickness, aerobic capacity, height, and weight. Significant correlations were found between the players’ ranking and speed (r = 0.430 – 0.475), specific agility and quickness (r = 0.626), speed endurance (r = 0.562), strength (r = –0.416), aerobic capacity (r = –0.581), flexibility (r = 0.352), height (r = –0.443), and weight (r = –0.293). Stepwise regression analysis indicated that specific agility and quickness accounted for almost 40% of the players’ ranking, while its combination with the players’ height accounted for 56%. The results imply the overall importance of anaerobic capabilities and tennis-specific movements to the young tennis players’ ranking. The results also emphasize the importance of tennis-specific tests to the young tennis players’ performance evaluation

13

ХАРАКТЕРИСТИКА ПІДГОТОВЧО-ТРЕНУВАЛЬНО-КОРЕКЦІЙНОГО ЕТАПУ РОБОТИ ЦЕНТРУ «СКІФ» СУМДПУ ІМЕНІ А. С. МАКАРЕНКА

75%

Анатолій К.

Педагогічні науки: теорія, історія, інноваційні технології

|

2017

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nr 1(65)

247-256

EN

The article describes the second phase of the work of the centre “SKIF”, which is aimed at stimulation of the leading physical qualities of pupils with sensory impairments. The attention is focused on defining their development factors as well as methods and means that solve remedial and sports challenges. The following research methods were used: theoretical – analysis of special pedagogical literature on the identified problem; practical – leading preparatory-training-remedial stage of work with children at the centre “SKIF”, empirical – calculations and comparative characteristics of the results. Throughout this stage in order to improve technology, enhance training effects and facilitate the integration of children with sensory impairments, experts in the field of physical culture practice repeated exercise. Their selection, the regulation of the duration and intensity determine the nature and degree of impact on the body of pupils, and develop their abilities. It is concluded that correctional-developing component of the pedagogical activities of the centre “SKIF” is closely connected with teaching children with sensory motor impairments and impairments in the development of motor skills. Therefore, at the second – preparatory-training-correction stage a complex of sports and remedial and rehabilitation activities is carried out, during which considerable attention is paid to the formation of high physical or athletic skills and achievement or to improving performance in the indoor football due to competitive activity. This puts high demands on the physical and psychological fitness of a footballer with a disability, so children playing indoor football and doing other kinds of sports activities in the centre “SKIF”, work on individual correction-rehabilitation programs. Each section shows the close connections of education, upbringing, correction of the broken functions and rehabilitation after physical loads. All measures in the frames of the programs provide comprehensive physical, mental and moral development of pupils. Prospects for further research in this direction are seen in the improvement of correction-rehabilitation and health-protection stages of the activities of the centre “SKIF”

14

The Functional Classification and Field Test Performance in Wheelchair Basketball Players

75%

Gil S. M. , Yanci J. , Otero M. , Olasagasti J. , Badiola A. , Bidaurrazaga-Letona I. , Iturricastillo A. , Granados C.

Journal of Human Kinetics

|

2015

|

tom 46

|

nr 1

219-230

EN

Wheelchair basketball players are classified in four classes based on the International Wheelchair Basketball Federation (IWBF) system of competition. Thus, the aim of the study was to ascertain if the IWBF classification, the type of injury and the wheelchair experience were related to different performance field-based tests. Thirteen basketball players undertook anthropometric measurements and performance tests (hand dynamometry, 5 m and 20 m sprints, 5 m and 20 m sprints with a ball, a T-test, a Pick-up test, a modified 10 m Yo-Yo intermittent recovery test, a maximal pass and a medicine ball throw). The IWBF class was correlated (p<0.05) to the hand dynamometry (r= 0.84), the maximal pass (r=0.67) and the medicine ball throw (r= 0.67). Whereas the years of dependence on the wheelchair were correlated to the velocity (p<0.01): 5 m (r= −0.80) and 20 m (r= −0.77) and agility tests (r= −0.77, p<0.01). Also, the 20 m sprint with a ball (r= 0.68) and the T-test (r= −0.57) correlated (p<0.05) with the experience in playing wheelchair basketball. Therefore, in this team the correlations of the performance variables differed when they were related to the disability class, the years of dependence on the wheelchair and the experience in playing wheelchair basketball. These results should be taken into account by the technical staff and coaches of the teams when assessing performance of wheelchair basketball players.

15

Changes in maximal aerobic fitness and students’ attitude towards physical effort during outdoor and indoor school lessons of Physical Education

75%

Pasek M. , Michalowska-Sawczyn M. , Nowak-Zaleska A.

Baltic Journal of Health and Physical Activity

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2014

|

tom 6

|

nr 1

24-33

EN

Background: The aim of the research was to determine an influence of an increased number of outdoor lessons of Physical Education on aerobic fitness and to evaluate students’ attitude towards endurance efforts. Material/Methods: In the presented research project a group of students participated in a school program of Physical Education on the basis of a higher number of lessons realized in the natural environment in the vicinity of school. The subjects were a group of 220 students from 4 schools of the Pomeranian Voivodeship, who were subjected to initial and final measurements during two school years. The most important assumption of the research stated better effects of outdoor classes of Physical Education in comparison with indoor classes and the shortage of experimental factor influence on the correlation change between objective and subjective indices of fitness and attitudes related to it. Results: In the experimental group the most distinct differences between initial and final tests concerned the endurance measurement, similarly to the control group in which, however, the improvement in the final test was less noticeable. The correlation among three analyzed variables was significant for both research groups. The comparison of results of students from the experimental and the control groups demonstrates a positive influence of outdoor lessons on the level of endurance and, to a lower degree, on the feeling of effort fatigue and mood. Conclusions: The research was conducted with a use of three research tools: the mood scale, Cooper’s test and the subjective fatigue feeling with finished effort scale that allow a positive verification of the presented hypothesis, which should be an encouragement for wider practicing of innovative activities to bring closer the assumed aims of Physical Education to the aims actually achieved.

16

Comparison of the General Fitness Level in Junior Kayakers with Different Sports Level Running title: Comparison of the fitness level in kayakers

75%

Rynkiewicz M. , Żurek P. , Biernacki J. , Pokrywka K. , Rynkiewicz T.

Central European Journal of Sport Sciences and Medicine

|

2019

|

tom 26

|

nr 2

57-65

EN

The objectives of this study were to see if the general performance of kayakers depends on the level of their specific preparation and to identify the parameters of general preparedness that determine specific preparation. The subjects were divided into 3 groups on the basis of the result of a specific test: paddling over a 2000-m distance. Group 2 included kayakers whose paddling time did not exceed ±1 SD for the whole sample, while group 1 included the best athletes with paddling times shorter than –1 SD and group 3 individuals who needed more than +1 SD to cover the 2000-m distance. The study included 55 junior flatwater kayakers, represented various sports classes. All athletes manifested a similar level of endurance running, power and endurance pull and push barbell, 30 m running tests. The only differing characteristic between all groups was the level of asymmetry in distance of ball throw from sitting position of at 29%, 45% and 66% in each group and paddling for 2000 m time. All athletes manifested a similar level of general fitness preparation. The only differing characteristic between all groups was the level of asymmetry in distance of ball throw from a sitting position.

17

Relationship between Gut-Microbiota and Sport Activity

75%

Mokarrami A. , Capacci A. , Trio B. , Della Morte Canosci D. , Merra G.

Central European Journal of Sport Sciences and Medicine

|

2024

|

tom 45

25-53

EN

Aim: The purpose of this umbrella review is to bring together the most recent reviews concerning the relationship between gut-microbiota and sport activity. Materials and Methods: A literature search was conducted through PubMed and focused on reviews and systematic reviews published between 2015 and June 2021 that dealt with the topic of microbiota and physical activity. Only articles written in English and published in peer-reviewed journals were considered. Key words related to the term microbiota alone or in conjunction with other terms such as "supplements", "diet", "probiotics", "prebiotics", "health", "physical activity", and "pathogens" were analyzed. The selection process was done first by analyzing the titles, then the abstracts, and finally the full text. Results: After screening the title and abstract, 29 articles were excluded. Therefore, 20 studies were included in the present umbrella review. The figure shows the steps of the selection process (Figure 1). The specifications of the presented articles are listed in Table 2. Conclusions: Exercise appears to be an environmental factor that can determine changes in the gut microbial composition with possible benefits for the host. Increased microbiota diversity improves metabolic profile and immunological responses and may provide a possible biomarker for health improvement. Exercise altered microbiota could be used to look for new approaches in the treatment of metabolic and inflammatory diseases.

18

Kryterium oceny wytrzymałości powłok PVD na udarowe obciążenia

63%

Krella A.

|

tom Vol. 31, nr 4

1046-1052

PL

W pracy przedstawiono wyniki badań doświadczalnych odporności kawitacyjnej powłok TiN i Cr-N. Badania przeprowadzono na stanowisku ze szczelinowym wzbudnikiem kawitacji. Dokonano analizy niszczenia twardych powłok na podstawie obserwacji mikroskopowych i znajomości zjawiska kawitacji. Wytypowano własności powłok mające kluczowe znaczenie w procesie degradacji powłok w warunkach powtarzających się, lokalnych i dynamicznych obciążeń. Zaproponowano parametr wytrzymałościowy, który łączy wszystkie kluczowe własności. Uzyskany parametr wykazuje bardzo dobrą zgodność z danymi eksperymentalnymi. Wzrostowi wartości tego parametru towarzyszy systematyczny spadek ubytków masy w testach kawitacyjnych.

EN

The article shows the results of cavitation erosion tests of TiN and Cr-N coatings. Tests were performed at cavitation chamber with a system of barricade. Analysis of degradation mechanism of hard coatings based on microscopic observation and knowledge of cavitation phenomena was made. The key properties of the TiN and the Cr-N coatings responsible on resistance against cavitation were appointed. The new resistance parameter for hard coatings against cyclic local and dynamic loading was proposed. The increase of the new parameter indicates a continuous improvement in the erosion resistance of the TiN and the Cr-N coatings.

19

Badanie mikrostruktury betonów przy zastosowaniu metody indentacji wielokrotnej

63%

Ranachowski Z.

|

2011

|

tom R. 83, nr 13

18-22

PL

W artykule skonfrontowano wyniki pomiarów parametrów mikrostruktury dwóch serii napowietrzonych mieszanek betonowych, takich jak: porowatość całkowita, współczynnik rozmieszczenia porów powietrznych, odporność na powierzchniowe łuszczenie z parametrami uzyskiwanymi w procedurze indentacji wielokrotnej. Indentacja wielokrotna umożliwia określenie mikrotwardości w obszarze matrycy i obszarze kruszywa, a także wyznaczenie powierzchniowego udziału obszarów o niskiej zwartości (LD), to jest obszarów o wysokiej porowatości. Te parametry uzyskiwane z badania metodą indentacji wielokrotnej można zastosować do oceny trwałości betonów badając np. próbki rdzeniowe, uzyskane z odwiertów. Pomiary metodą indentacji wielokrotnej można prowadzić w sposób zautomatyzowany. Przedstawione wyniki badań wskazują na obniżenie odporności na środowiskowe czynniki agresywne w kompozycjach o podwyższonym współczynniku LD.

EN

The paper presents the results of investigation of parameters of microstructure of two series of air pertained concrete mixes. The following parameters were examined: volumetric porosity, air pores spacing coefficient, surface scaling endurance - confronted to those derived from the statistical indentation procedure. That procedure is intended to determine the microhardness of concrete matrix, aggregates area and of the percental content of a component called low density area (LD), characterizing the high porosity clusters. The parameters obtained with application of statistical indentation method can be used to assess the endurance of concrete by testing of core samples drilled out of the massive constructions. There is a possibility to automate the described method. The presented test results suggest that the compositions that reveals the increased LD coefficient also tend to demonstrate the lower resistance to environmal aggression agents.

20

Life cycle increasing of mechanical components using thermal coatings with recasts

63%

Herditzky A. , Kickova M.

|

2008

|

tom z. 73 [253]

117-122

EN

This article concerned with proposition of friction and deterioration of functional components surfaces in adhesive deterioration area and contact endurance. It's centered for possibilities how to decrease deterioration and extend a life cycle of component choosing appropriate material, component surface adjustment, or abrasion-resistant coatings painting with expressively better properties against basic material.