Evaluation performance of ballistic movements - variables for assessement the accuracy and kicking velocity

Primarni cilj izvršenih istraživanja je bio da se ispita pouzdanost i osetljivost varijabli za direktnu procenu preciznosti i brzine šuta, kao dve važne karakteristike šuta. Sekundarni cilj ovih istraživanja je bio da se utvrdi minimalan broj ponavljanja koji je dovoljan za prihvatljivu pouzdanost podataka u protokolima za procenu preciznosti i brzine šuta. Pouzdanost varijabli za direktnu procenu preciznosti i brzine šuta u fudbalu (Eksperiment 1) U istraživanju pouzdanosti varijabli za procenu preciznosti i brzine šuta testirane su hipoteze: 1) varijable za direktnu procenu preciznosti, zasnovane na merenju standardnih grešaka, imaju umerenu pouzdanost i 2) varijable za direktnu procenu brzine šuta imaju visoku pouzdanost. U istraživanju su učestvovala 53 fudbalera, sa šireg spiska nacionalne selekcije uzrasta 12 i 13 godina. Apsolutna (AG), konstantna (KG) i varijabilna (VG) greška su korišćene za procenu sposobnosti pogađanja u metu, dok su brzina leta lopte pri maksimalnom šutu (BLLmax), brzina leta lopte pri preciznom šutiranju (BLLprec), kao i međusobni odnos ove dve varijable (BLLprec/BLLmax) korišćeni za vrednovanje brzine šuta. Rezultati pouzdanosti i minimalanog broja ponavljanja, dobijeni u ovom istraživanju, ukazali su da AG i VG mogu biti varijable korišćene u rutinskim testiranjima za procenu karakteristika šuta. Nasuprot tome, utvrđeno je da zbog izuzetno niske pouzdanosti KG nije dovoljno dobra varijabla za korišćenje u rutinskim testiranjima procene preciznosti. Kada su u pitanju varijable brzine šuta nogom BLLmax, BLLprec i BLLprec/BLLmax, one mogu biti korišćene u rutinskim testiranjima karakteristika šuta, na šta su ukazali pouzdanost rezultata i potreban minimalan broj ponavljanja. Na osnovu dobijenih rezultata može se zaključiti da su varijable za direktnu procenu preciznosti i brzine šuta evaluirane i prihvatljive za dalju primenu u istraživanjima, kao i u praksi, gde se mogu koristiti u kreiranju valjanih i efikasnih vii protokola testiranja, posebno kada se uvaže podaci o predikciji broja neophodnih ponavljanja...The primary aim of the present study was to investigate the reliability and sensitivity of variables for the direct assessment of the kicking accuracy and velocity, while the secondary aim was to determine the minimum number of repetitions that is sufficient for acceptable reliability of the applied protocols for assessing the kicking accuracy and velocity. Reliability of the variables for direct assessement of kicking performance in soccer (Study 1) In this study we tested two hypotheses: 1) the variables for the direct assessment of kicking accuracy based on the measurement of the standard errors will reveal moderate reliability, while 2) the variables for direct assessment of the kicking velocites will reveal highly reliability. The study included 53 young soccer players who were the members of the wider selection of national team aged 12 and 13 years. Absolute error (AE), variable error (VE), and constant error (CE) were evaluated as the variables of kicking accuracy, whereas the kicking velocity variables involved the maximum ball velocity (BVmax), the ball velocity during accurate kicks (BVacc) and their mutual ratio (BVacc/BVmax). Results suggested low-to-moderate reliability of the accuracy and high reliability of the velocity variables. Since the evaluated variables should have a property of face validity, the findings obtained generally suggest that AE (and perhaps VE, as the measures of kicking accuracy), and BVmax, BVacc and BVacc/BVmax (as the measures of kicking velocity) could be used for routine testing of kicking performance in soccer. Further development of the evaluated variables of kicking performance could be based on the involvement of other kicking techniques, as well as on the testing the athletes of different ages, levels of skill, or sport specialization..

Analysis of training load and performance in designing smart bodyweight power training: effects of set structure in vertical jumping sessions

The purpose of this study was to investigate the role of set structures in designing bodyweight power training (BWPT). Specifically, we compared the effects of the cluster set structure undulating variant (CSSUV) and the traditional set structure (TSS) on training load and performance during vertical jumping sessions. Sixteen active males participated in this study. We designed four training sessions that consisted of 144 countermovement jumps distributed into 12 sets, where the number of repetitions varied for the CSSUV sessions, whereas for TSS sessions the number of repetitions was fixed. In addition, both of the applied set structures included sessions with short (60 seconds) and long rest periods (120 seconds), while training volume was separately analysed for the first six sets (small volume) and the last six sets (large volume). External load, internal load, and performance variables were calculated. The results suggest that CSSUV allows superior utilization of applied external load, reduction of internal load and overall higher performances that are maintained during entire training session compared to TSS (p<.05). The present study provides important findings about advantages of CSSUV over TSS in terms of external load, internal load, and performances during vertical jumping sessions, and therefore, it might be more suitable approach to designing BWPT

Anthropometric and Physical Performance Profiles of Elite Karate Kumite and Kata Competitors

Karate tournaments consist of two equally important karate disciplines: the kumite and kata competitions. Due to being based both on the distinctive selection of movement techniques and their kinematic and kinetic patterns, we hypothesized that the elite kumite and kata competitors could differ regarding their anthropometric and physical performance profiles. Thirty-one senior male karate competitors of the national karate team (kumite n = 19; kata n = 12) participated in this study. The tests applied included both the assessment of anthropometric (body height, mass and body mass index) and the following physical performance measurements: the adductor and hamstring flexibility (sideward leg splits test), speed and acceleration (20-m sprint test with 10-m acceleration time), explosive power (countermovement and standing triple jump), agility ("T"- test) and aerobic endurance (20-m multistage shuttle run test). The kumite competitors revealed a larger body size through body height (p = 0.01) and mass (p = 0.03), while the differences in body composition were non-significant. The kumite competitors also demonstrated higher acceleration (p = 0.03) and explosive power (standing triple jump; p = 0.03). A 6-7 degrees higher flexibility of the kata competitors remained somewhat below the level of significance (p = 0.09). The findings could be interpreted by the distinctive differences in the movement techniques. Specifically, a higher explosive power could be beneficial for kumite, while both a smaller stature and higher flexibility (particularly of the lower extremity) could be important for the exceptionally low postures of the kata competitors. Although further elucidation is apparently needed, the obtained finding could be of importance for both the early selection and training of karate competitors

Force-Velocity Profiles of Elite Athletes Tested on a Cycle Ergometer

The present study explored the sensitivity of the force-velocity (F-V) modelling approach obtained from maximal sprints on a leg cycle ergometer to detect selective changes of the mechanical capacities of the lower body muscles associated with high-level training. Specifically, we assumed that the F-V relationship parameters, such as maximum force (F0 ), velocity (V0 ), power (PM) and slope, would differ among individuals of different high-level training backgrounds. In total, 111 elite athletes divided into four groups (Combat sports, Athletic sprints, Team sports and Physically active) performed maximal sprints on a leg cycle ergometer loaded with 7%, 9%, and 11% of body weight. The findings obtained suggest an exceptionably strong and linear F-V relationship in most of the participants (r > 0.95), while higher PM have been found in all groups of athletes compared to the Physically active group (p < 0.05). In addition, sport-specific F-V profiles have been observed in athletes that belong to distinctively different sports (i.e. higher F0 and forceoriented slope for strength-trained Combat sports and higher V0 for speed-trained Athletic sprints). To our knowledge, this is one of the rare studies that evaluate the F-V profiles with such a large sample of elite athletes obtained from commonly used task such as maximal sprints on a leg cycle ergometer. The results obtained support a high sensitivity of the F-V modelling approach to distinguish among elite athletes with different training histories