11 research outputs found
Acute effect of basketball-specific exercise on lower limb injury risk mechanisms in male basketball players U16 and U18
Get PDFThe aim of this study was to examine and compare the acute effects of basketball-specific fatigue on muscular stiffness and reactive strength in male adolescent basketball players of two age categories. Reactive strength, expressed by means of the reactive strength index (RSI), and leg stiffness (LS) as mechanisms associated with the risk of ACL injury were measured in eleven players of the U16 category (age 16.1 ± 0.4 years; body height 185 ± 6.5 cm; body mass 74.3 ± 9.9 kg) and ten players of the U18 category (age 17.7 ± 0.4 years; body height 187 ± 5.7 cm; body mass 79.7 ± 7.4 kg) pre and post simulated basketball match play (SBFP28). RSI was determined by a drop jump test, LS by a 20 sub-maximal two-legged hopping test. No significant effects of SBFP28 on the monitored parameters were observed with the exception of RSI in U16 (p = 0.013, r = 0.53). Similarly, there were no significant differences in the fatigue-related responses to SBFP28 for RSI and LS between the age groups. These results indicated that irrespective of age, the stabilization function of the knee muscles was not impaired and consequently the risk of ACL injury was not increased
The Mission in the Gospel of John
No full textInstitute of oecumenical studiesInstitut ekumenických studiíProtestant Theological FacultyEvangelická teologická fakult
Operačné riziko a jeho postavení v systému řízení rizik ve finanční instituci
No full textImport 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Ekonomická fakulta. Katedra (154) financ
Heart rate and time-motion analyses in top junior players during basketball matches
No full text<strong>BACKGROUND</strong>: Basketball performance can be classified as an intermittent physical activity due to the changing situational game conditions and the number of intervening variables. It is necessary to have detailed knowledge about the performance of basketball players during a match as a background for more specific planning of the training process. <strong>OBJECTIVE</strong>: The aim of this study was to analyse the indicators of internal and external load of basketball player’s performance during a match of U18 top men basketball players as a background for the planning of specific training processes. <strong>METHODS</strong>: Thirty-two Czech top junior basketball players (male, aged 16.88 ± 0.72 years) participated in this research. The heart rate was recorded and time-motion analysis was conducted during six warm-up matches. <strong>RESULTS</strong>: The average heart rate was measured to be 167.47 ± 13.01 beats • min.–1, which corresponded to 85.06 ± 6.40% of peak heart rate. The percentages of the total time spent over and under 85% were 63.12% and 36.88%, respectively. Average distance covered was measured to be 5,880.91 ± 831.01 meters. The average work : rest ratio was 1 : 7.95 ± 1.83, ranging from 1 : 4.80 to 1 : 10.92. <strong>CONCLUSIONS</strong>: The results from these matches suggest that the exercise intensity and sprint activity observed during junior basketball are dependent on the player's position and partly on the level of the performance. The heart rate during a match was not dependent on the positions, however, time-motion analysis revealed significant differences between three basketball positions during a match. The combination of heart rate and time-motion analysis is recommended
Reliability and validity of a basketball-specific fatigue protocol simulating match load
No full textBackground: Research on the amount and type of fatigue caused by match load depends on protocols based on time-motion analysis of match performance in a given sport. The role of these protocols is to accurately simulate specific player match load, which is, contrary to a match, identical for all participants. Objective: The purpose of the study was to determine the reliability and validity using a basketball-specific fatigue protocol simulating player's performance during a basketball match. Methods: The study involved a total of 25 male basketball players (age 17.4 ± 1.5 years; body height 185.1 ± 7.4 cm and body mass index 22.1 ± 0.3 kg ⋅ m-2) of U17 and U19 categories. The participants performed a specific basketball fatigue protocol twice during 14 days consisting of four periods separated by breaks as in a basketball match. Each period contained a stage with maximum intensity activities followed by a stage of medium intensity and low intensity. During the protocol, heart rate was recorded and time intervals of maximum, medium and low intensity were measured. Results: The relative reliability measurement pointed to high intra-individual stability of the results, when intraclass correlation coefficient varied from .71 to .92. The typical error of measurement showed that the players should be able to repeat the measurement with less than 1.31 s (0.82%) in total time, 0.17 s (2.73%) in sprint time, and 1.32% (1.19%) for percentage of heart rate. The values 1.68 (38.35%) of Sprint decrement showed very low repeatability.Conclusion: Measurements using a fatigue protocol showed high validity, reliability, and agreement of repeated measures
Changes of explosive strength in professional basketball players after a six week training cycle with plyometric training and resistance training
No full textBACKGROUND: Explosive strength of the lower extremities and agility are important parts of game performance in basketball. Although numerous studies have focused on the assessment of the training effect of plyometric training, studies focusing on elite players are missing. OBJECTIVE: The aim of the study was to find out what changes in explosive strength of the lower extremities take place after a 6 week strength training with plyometric exercises and resistance exercises in elite basketball players. METHODS: Elite basketball players (n = 12; age 24.71 ± 1.5 years; height 197.0 ± 7.6 cm; weight 95.8 ± 8.1 kg) performed during pre-season a 6 week training program with plyometric exercises and resistance exercises which were conducted biweekly during the pre-season. The changes in explosive strength were measured by the squat jump without arms, the counter movement jump without arms, the counter movement jump free arms and the 2 step run up jump. The players participated in two measurements. The 1st (pretesting) was performed on the first day of pre-season and the 2nd (posttesting) was completed two days after terminating the PT programme. The differences between the average values of the monitored parameters were determined by the Wilcoxon paired test. To calculate the effect size formula according to Fritz, Morris, and Richler (2012): R = Z/√N was used. RESULTS: Analysis of intra-group changes confirmed significant differences between the two measurements in tests of vertical jump squat (Z = 2.58, p = .01, r = .75), vertical jump from the point of the swing arm (Z = 2.49, p = .01, r = .72) and vertical jump from place without the swing arm (Z = 2.75, p = .01, r = .79). In case of the two step run up jump significant differences were not found (Z = 1.60, p = .11, r = .56). Analysis of intra-individual changes showed the significant interindividual differences in the changes of the explosive power of the lower limbs after a 6 week training. The improvement in all tests was observed in nine of the twelve players, oppositelly the deterioration in one player. CONCLUSIONS: The results of the study in elite basketball players have confirmed that the inclusion of plyometric exercises and exercises with additional resistance in the preparatory period may lead to significant changes in explosive power even elite senior basketball players
Reliability of specific on-ice repeated-sprint ability test for ice-hockey players
No full textBackground: Repeated sprint ability tests are today widely used to evaluate the performance capability in team sports. Objective: The aim of this study was to determine the reliability of a specific ice hockey test, which indicates the agility and repeated-sprint ability of the players. Methods: Twenty four highly trained junior ice hockey players (age = 17.68 ± 1.52 years; BMI = 23.8 ± 1.92 kg . m-2) participated in the study. Each participant was assessed for specific on-ice repeated-sprint ability test 12 × 54 m with 30 s rest. Intraclass correlation coefficient (association between two repeated measurements) and coefficient of variation were calculated to assess the reliability of the test. Results: All intraclass correlation coefficients were .78 for sprint decrement and .98 for total time and the best time, the coefficient of variation was 1.52% for best sprint time, 1.31% for total time and 19.3% for sprint decrement variable. Conclusions: The results suggest the high reliability of the ice hockey agility test expressed by the best sprint time and repeated-sprint ability by the total time and less reliability of sprint decrement
External and internal load of playing positions of elite female handball players (U19) during competitive matches
No full textBackground: Effective training depends on knowledge of the sport's requirements. Physical (external load) and physiological (internal load) analyses will provide valuable data that can be used for other research and to improve specific training requirements. Handball is an intermittent sport game, and it is important discover the factors, that affect the performance in a handball match. Objective: The aim of this study was to analyze and compare motion and heart rate of playing positions of female handball players during competitive matches.Methods: Heart rate and motion-time analyses were examined during six competitive matches of the Czech elite female handball league (U19). The average (± SD) age of the fourteen participants was 17.9 ± 0.3 years; their average weight 65.4 ± 6.9 kg, and their average height was 169.6 ± 6.9 cm. Results: During the matches, the longest average distance was covered by backs (7,138.3 ± 334.4 m), followed by wings (6,915.3 ± 362.2 m) and pivots (6,337.1 ± 477.3 m). A statistically significant difference was found only between backs and pivots (p = .01). The average heart rate of players in the most loaded position, pivots, was 185.3 ± 9.2 beats ⋅ min<sup>-1</sup>, corresponding to 90.1 ± 4.3% of HR<sub>max</sub>. The second most loaded playing position were wings with the average heart rate of 183.8 ± 6.2 beats ⋅ min<sup>-1</sup>, corresponding to 89.9 ± 3.5% of HR<sub>max</sub>. The average heart rate of backs was 182.9 ± 8.4 beats ⋅ min<sup>-1</sup>, corresponding to 89.2 ± 4.4% of HR<sub>max</sub>. Conclusions: The results from the presented study show that handball is a game of intermittent high intensity and physiological profile where more than 80% of each game is spent in load-intensity above 85% HR<sub>max</sub>. Between playing positions are differences in intensity of load, covered distance and in speed categories
A new view on the quality of Jacík's test [Nový pohled na kvalitu Jacíkova testu]
No full textBACKGROUND: A self-assessment of physical fitness requires a search for motor tests which do not make high material, spatial and skill demands necessary for tests' realization. In this manner, Jacík's test (JT) appears to be an appropriate one. Nevertheless, existing information about the test quality is not complete. Based on the motion content of this test, the test performance can be considered to be determined by the level of aerobic fitness. OBJECTIVE: The aim of this study is to assess the reliability of JT and to determine degree of influence of aerobic fitness on JT performance. METHODS: Eighty four PE university students completed the study: 43 female (participated in the validity study; 22.2 ± 2.0 yr; BMI = 23.2 ± 2.5 kg/m2; JT performance = 79.1 ± 9.2 points; VO2max = 44.6 ± 4.7 ml/kg/min) and 41 males (participated in the reliability study; 21.5 ± 1.2 yr; BMI = 25.2 ± 1.6 kg/m2; JT performance = 83.9 ± 8.2 points in the first trial and 87.5 ± 9.1 points in the second trial respectively). The degree of influence of aerobic fitness on the performance in JT is expressed as association between the performance in JT and VO2max estimation (measured by Maximal exercise test realized on a treadmill). The objectivity and the relative reliability of JT are expressed by ICC. Characteristics SEM and Bland-Altman's 95% limits of agreement were computed to assess absolute reliability of JT. RESULTS: A little of shared variability of JT and VO2max respectively was found out (only 13.3%). ICCinter-raters = 0.997 indicates a high degree of objectivity (inter-rater reliability). The result of ICCinter-trials = 0.790 points to a 'questionable' relative reliability. The systematic error of measurement equals to 3.54 points. Both SEM (3.96 points) and Bland-Altman's 95% limits of agreement (-9.2, 16.3) point out to the unsatisfactory degree of absolute reliability. CONCLUSION: Mainly due to the low degree of the test's reliability (both relative and absolute), JT is not an accurate tool for assessing physical fitness in PE university students. The interpretation of testing results could be misleading.[VÝCHODISKA: Sebehodnocení tělesné zdatnosti vyžaduje hledat motorické testy, které nekladou vysoké materiální, prostorové ani dovednostní nároky na jejich provedení. Jacíkův test (JT) se v tomto ohledu jeví jako velice výhodný. Dosavadní poznatky o vlastnostech tohoto testu však nejsou úplné. Vzhledem k pohybové náplni JT lze předpokládat, že výkon v tomto testu bude do určité míry podmíněn také úrovní aerobní zdatnosti. CÍLE: Cílem studie je posoudit reliabilitu JT a stanovit podíl aerobní zdatnosti na testovém výkonu. METODIKA: Výzkumný soubor tvoří dvě samostatné skupiny vysokoškoláků: 43 žen (stanovení validity testu; 22,2 ± 2,0 let; BMI = 23,2 ± 2,5 kg/m2; výkonnost v JT = 79,1 ± 9,2 bodů; VO2max = 44,6 ± 4,7 ml/kg/min) a 41 mužů (stanovení reliability testu; 21,5 ± 1,2 let; BMI = 25,2 ± 1,6 kg/m2; výkonnost v JT = 83,9 ± 8,2 bodů při prvním, resp. 87,5 ± 9,1 bodů při druhém pokusu). Podíl aerobní zdatnosti na výkonu v JT je vyjádřena mírou asociace mezi výkonem v JT a odhadem VO2max (stanoveno využitím Maximálního zátěžového testu na běhátku). Objektivita a míra relativní reliability je vyjádřena pomocí ICC. SEM, a Bland-Altmanovy 95 % limity shody byly stanoveny k posouzení absolutní reliability. VÝSLEDKY: Byl zjištěn nízký podíl společné variability JT a VO2max (pouhých 13,3 %). ICCinter-raters = 0,997 ukazuje na vysokou míru objektivity (inter-rater reliability). Výsledek ICCinter-trials = 0,790 naznačuje 'pochybnou úroveň' relativní reliability. Systematická chyba měření dosahuje hodnoty 3,54 bodu. Na neuspokojivou míru absolutní reliability ukazuje jak SEM = 3,96 bodu, tak i šíře Bland-Altmanových 95 % limitů shody (-9,2; 16,3). ZÁVĚRY: JT není vhodný nástroj pro hodnocení motorických předpokladů u vysokoškoláků, a to především z důvodů nízké reliability (relativní i absolutní). Interpretace výsledků tohoto testu by byla zavádějící.
The effects of a 6 week plyometric training programme on explosive strength and agility in professional basketball players
No full text<strong>BACKGROUND</strong>: Explosive strength of the lower extremities and agility are important parts of game performance in basketball. Although numerous studies have focused on the assessment of the training effect of plyometric training, studies focusing on elite players are missing. <strong>OBJECTIVE</strong>: The aim of the study was to find out what changes in explosive strength of the lower extremities take place after a 6 week plyometric training applied in training units during the pre-season in elite basketball players. <strong>METHODS</strong>: Elite basketball players (N = 12, age 24.36 ± 3.9 years, height 196.2 ± 9.6 cm, weight 92.9 ± 13.9 kg) performed a 6 week plyometric training (PT) programme predominantly focused on explosive strength of the lower body and upper body and was conducted in sixteen training units during pre-season. The changes in explosive strength were measured by the Counter Movement Jump Free Arms test and Two Step Run Up Jump test; agility was measured using the “T” Drill test and Hexagonal Obstacle test. The players participated in three measurements. The 1st (pretesting) was performed on the first day of pre-season, the 2nd (post-testing) was done two days after completing the PT programme and the 3rd (post-testing) six weeks after completing the PT programme. Friedman’s ANOVA for repeated measurements was used to determine the significance of differences between the measurement sessions (p < .05). <strong>RESULTS</strong>: A significant effect of the training programme was observed only for the Hexagonal Obstacle test (p = .01). A post hoc analysis revealed a significant increase in test performance between the 1st and 3rd measurement (p < .01) and between the 2nd and 3rd measurement (p < .01). <strong>CONCLUSIONS</strong>: The results of the study of elite basketball players did not positively support the assumption that plyometric exercises can be an effective tool for the improvement of explosive strength and agility. However, in some players the improvements corresponded to average improvements after training programmes presented in literature
