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This study aimed to explore the effects of competitive match play and subsequent training during typical competitive microcycle on landing biomechanics in female youth handball players. A group of 11 elite female youth players (age: 14.3 ± 0.6 years; stature: 165.9 ± 8.1 cm; body mass: 58.4 ± 10.6 kg; maturity offset: 0.4 ± 0.8 years) were tested prior to a competitive match, immediately after the match, 48 h after the match, 96 h after the match, and before the next match. The players performed two analyzed trials of a single leg (preferred) counter movement jump. The “Landing Error Scoring System” (LESS) was used to analyze the participants’ landing biomechanics. Results: There was no significant effect of a competitive handball match on LESS (Z = 0.28; p = 0.78). No statistically significant difference in LESS was found between the first and the last measurement (Z = 1.01; p = 0.31). No significant main effect of time was found for landing biomechanics in the observed eight-day period (χ2 = 4.02; p = 0.40). The results of the study indicate that a model of weekly loading during in-season, including competitive match play, does not decrease lower limb biomechanics during landing and does not contribute to an increased risk of anterior cruciate ligament injury in female youth handball players during a competitive microcycle.

The main goal was to determine anaerobic and aerobic improvement of young soccer players after six-week high volume (HVT) or small sided games (SSG) training intervention. One hundred and one highly trained youth soccer players (16.2 ± 1.3 years) were divided into SSG (n = 51) and HVT groups (n = 50) and according to age into an under sixteen subgroup (U16), under seventeen subgroup (U17), and under nineteen subgroup (U19). The performance was assessed by Yo-Yo intermittent test, Repeated sprint ability test (RSA), and K-test before and after both training interventions. For U16 the SSG group recorded significant improvements in the K-test (0.64 ± 0.56 s; p = .04) and RSA (0.15 ± 0.43 s; p = .01). For U19 the SSG group recorded the same improvements, in the K-test (0.43 ± 0.57 s; p = .007), RSA (0.21 ± 0.22 s; p = .048), and Yo-Yo test (127.25 ± 17.87; p = .049). HVT improved aerobic performance when the Yo-Yo test was significantly better after intervention at U17 (199.00 ± 111.83 m; p = .030), U19 (88.40 ± 66.38 m; p = .049). In total, the HVT group spent 621 min (56.45 ± 5.01 min) of aerobic training and the Small sided game group spent 291 min (26.45 ± 8.61 min) of small sided games focused on aerobic performance. This study showed that both SSG and HVT training interventions were effective for aerobic improvement for the U19 category, but not for younger players. SSG was identified to be more appropriate to fitness development of soccer players.

Background: Basketball players are among the players with a great risk of anterior cruciate ligament injury due to the high-intensity manoeuvres which have been identified as very common factors preceding this injury. Objective: This study aimed to assess differences in leg stiffness and reactive strength throughout a competitive season in youth basketball players and to assess the effect of age and performance level on these variables. Methods: The research study involved a total of 48 male basketball players from the age group U14 and U16 played the first and second highest league in Czech Republic. Reactive strength index (RSI) and leg stiffness were measured at the beginning of the season, mid-season, and at the end of the season. Analysis of Variance for repeated measures was used to identify the influence of age, season phases, and levels of performance to monitored variables. Results: The results showed significant changes among season phases in RSI (F = 4.48, p = .014) and relative leg stiffness (F = 7.17, p = .002) in observed players, however significantly higher values at the end of the season than at its beginning were found in RSI only (p = .014). Differences between subgroups with different levels of performance were not significant in both categories as well as age differences. Conclusions: The current study did not point-out to significant changes among season phases in reactive strength and leg stiffness in adolescent basketball players. The study did not confirm that reactive strength and leg stiffness is gradually improving during adolescence and suggestion that level of performance positively influences reactive strength and leg stiffness was confirmed only in the case of reactive strength.

Background: 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.

Background: Effective training depends on knowledge of a sport's requirements. Small-sided games (SSG) are a spontaneous form of specific training, where exercise intensity can be manipulated mainly by modifying external factors. In SSG the players develop technical and tactical skills in the similar situations, such as during a match and can also develop their physical skills. Objective: The purpose of this study was to examine the distance covered and physiological response of altering the number of youth male players during small-sided team handball games with modified rules. Methods: The subjects consisted of 12 male youth team handball players (age 16.6 ± 0.5 years) playing the first league for youth male players in the Czech Republic. The study was conducted during six weeks (one training session per week). Only three SSG were played in each training session. The SSG were played, first with five players on each side (5 vs. 5), then four (4 vs. 4), then three (3 vs. 3). Each game was four minutes long, followed by three minutes of passive rest. Results: The players covered the greatest distance (520.6 ± 61.4 m) in the SSG 3 vs. 3. There was a difference in the distance covered between players in the 3 vs. 3 SSG and the other SSG (4 vs. 4 and 5 vs. 5) (p = .041 and p = .043, respectively). In individual speed zones a difference occurred only in the first and third speed zone and always among the 3 vs. 3 and 5 vs. 5 SSG (p = .034 and p = .044), respectively. The highest average intensity (87.9 ± 4.8% HRmax) was in 3 vs. 3 SSG. Loading of the players in 5 vs. 5 was lower compared to 4 vs. 4 (p = .035) and 3 vs. 3 (p 90% HRmax) between 3 vs. 3 and 5 vs. 5 SSG (p = .041). Conclusions: These results indicate that changing the number of players during SSG with modified rules in youth team handball may be used to manipulate the physiological response during youth team handball training.

Background: 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-1, corresponding to 90.1 ± 4.3% of HRmax. The second most loaded playing position were wings with the average heart rate of 183.8 ± 6.2 beats ⋅ min-1, corresponding to 89.9 ± 3.5% of HRmax. The average heart rate of backs was 182.9 ± 8.4 beats ⋅ min-1, corresponding to 89.2 ± 4.4% of HRmax. 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% HRmax. Between playing positions are differences in intensity of load, covered distance and in speed categories.

Background: Small-sided games belong to specific training where exercise intensity can be manipulated mainly by modifying external factors. To ensure suitable usage of small-sided games in practice, we have to know the variables, which could influence internal responses and external loads. Objective: The purpose of this work is to determine the influence of opponents of different levels on internal response and external load during a 4-a-side soccer game. Methods: Twenty physical education and soccer coaching students (age 22.53 ± 1.02 years; body mass index 20.83 ± 2.13 kg ⋅ m-2; peak heart rate 195.26 ± 6.05 beats ⋅ min-1) participated in the study. Heart rate, distance covered, global rate of perceived exertion, and technical demands (passes, shots, steals, turnovers) were monitored. The participants were divided into two higher level teams and two lower level teams according to experts' perfomance ranking. Results: The results showed significantly lower average heart rate achieved by higher level teams in the 4-a-side game against lower level opponents compared to against higher level teams. Then lower level teams reached significantly higher average heart rate in the 4-a-side game against higher level teams than in mutual lower level team 4-a-side game. We found out significantly higher distance covered by lower level teams in 4-a-side game against higher level teams than in lower level teams mutual 4-a-side game. Conclusions: The results of this study demonstrated that the performance level of opponents influence internal and external load of the players. The higher level of opponents increases the work load of lower level teams.

Background: Small-sided games (SSG) are spontaneous forms of specific training where exercise intensity can be manipulated mainly by modifying external factors. When using the SSG, there is a risk that the variability of intensity between players and on repetition of SSG may lead to some players training at inappropriate exercise intensities. Objective: The purpose of this study is to determine intra-individual repeatability and inter-individual variability in exercise intensity in small-sided 4on4 football games. Methods: Twenty five highly trained junior football players (age 17.68 ± 1.52 years; BMI 23.8 ± 1.92 kg . m-2) participated in the study. Distance covered (software package Video Manual Motion Tracker 1.0) and heart rate (HR, expressed as a percentage of peak heart rate) were measured. All participants completed three measurements of 4-a-side games for three consecutive weeks. Results: The high intraclass correlation coefficient value (Heart rate [HR]: ICC = .88, 95% CI [.65, .94]; Distance covered [DC]: ICC = .76, 95% CI [.66, .96]) implies a very high level of intra-individual repeatability. The Pearson's correlation coefficient value (HR: r = .93; DC: r = .85) indicates a high correlation between the results of any measurement. Bland and Altman's 95% limits of agreement were ± 10.32 beats . min-1 and ± 65.46 m of distance covered. Conclusions: The results of this study demonstrated that measured SSG elicit consistent heart rate responses and external load of the players.

Background: 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.

BACKGROUND: 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.

BACKGROUND: 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 plyometric training applied in training units during the pre-season in elite basketball players. METHODS: 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 RESULTS: 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 CONCLUSIONS: 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.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

BACKGROUND: 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 quality of specific endurance preparedness could be verified by decrease of performance due to fatigue manifestation at the end of each quarter. The aim of this study was to determine validity and reliability of fatigue manifestation of basketball players during last three minutes of each quarter during game-based drill. Total of 86 male basketball players participated in this study. Every participant was monitored by the Sage Analytics to find activity demands during a game-based drill. One-way analysis of variance and reliability indexes were calculated. According to validity analysis, significantly growing total distance (F=11.04; p=.001; η2p=.18) and descending precent of distance decrement (F=5.46; p=.005; η2p=.11), and fatigue index (F=14.07; p=.001; η2p=.28) with increased level of performance and at the same time growing total distance and descending precent of distance decrement for backcourt players. The reliability analysis showed that TD (F=20.60; p=.001; η2p=.17) and precent of distance decrement (F=5.80; p=.018, η2p=.05) are reliable instrument to express fatigue during game-based drill simulating match workload. The values of ICC were found very high inter-rater reliability for distance decrement (ICC=.818), high for total distance (ICC=.695). Total distance and distance decrement are valid and reliable instruments to express fatigue during game-based drill simulating match workload.

Small-sided games are a specific form of training in which exercise intensity can be manipulated mainly by modifying external factors. The aim of this study was to determine the influence of a number of players during small sided futsal games on metabolic responses and distance covered at elite senior futsal players. Fifteen top level Czech futsal players (males, aged 26.81±5.30; body height = 176.10±4.34 cm; body weight = 71.31±5.30 kg, and peak heart rate=191.23±5.4 beats•min-1) participated in the study. Heart rate, blood lactate concentrations, distance covered, and rate of perceived exertion were monitored during small-sided futsal games. We found significant differences between blood lactate concentration values and perceived exertion; it was significantly higher during 3vs3 and 4vs4 small-sided games than during 6vs6 games. When we compared the distance covered by players, we found significantly higher distance covered during 4vs4 than in 6vs6 games. The results of this study demonstrated that the small-sided games 3vs3 and 4vs4 were valuable tools to develop specific futsal fitness. As the most intensive, the 4-a-side game was found.