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Purpose: The purpose of this study was to examine the relationship between ball-throwing velocity during a 3-step running throw and dynamic strength, power, and bar velocity during a concentric-only bench-press exercise in team-handball players. Methods: Fourteen elite senior male team-handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric-only bench-press test with 26, 36, and 46 kg, as well as having 1- repetition-maximum (1-RMBP) strength determined. Ball-throwing velocity was evaluated with a standard 3-step running throw using a radar gun. Results: Ball-throwing velocity was related to the absolute load lifted during the 1-RMBP (r = .637, P = .014), peak power using 36 kg (r = .586, P = .028) and 46 kg (r = .582, P = .029), and peak bar velocity using 26 kg (r = .563, P = .036) and 36 kg (r = .625, P = .017). Conclusions: The results indicate that throwing velocity of elite team-handball players is related to maximal dynamic strength, peak power, and peak bar velocity. Thus, a training regimen designed to improve ball-throwing velocity in elite male team-handball players should include exercises that are aimed at increasing both strength and power in the upper body. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the contribution of upper extremity, trunk, and lower extremity movements in overarm throwing in team handball. In total, 11 joint movements during the throw were analyzed. The analysis consists of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timing during the throw. Only the elbow angle (extension movement range) and the level of internal rotation velocity of the shoulder at ball release showed a significant relationship with the throwing performance. Also, a significant correlation was found for the timing of the maximal pelvis angle with ball velocity, indicating that better throwers started to rotate their pelvis forward earlier during the throw. No other significant correlations were found, indicating that the role of the trunk and lower limb are of minor importance for team handball players. [ABSTRACT FROM AUTHOR]

This investigation examined step-by-step kinematics of sprint running acceleration. Using a randomised counterbalanced approach, 37 female team handball players (age 17.8 ± 1.6 years, body mass 69.6 ± 9.1 kg, height 1.74 ± 0.06 m) performed resisted, assisted and unloaded 20-m sprints within a single session. 20-m sprint times and step velocity, as well as step length, step frequency, contact and flight times of each step were evaluated for each condition with a laser gun and an infrared mat. Almost all measured parameters were altered for each step under the resisted and assisted sprint conditions (η2 ≥ 0.28). The exception was step frequency, which did not differ between assisted and normal sprints. Contact time, flight time and step frequency at almost each step were different between 'fast' vs. 'slow' sub-groups (η2 ≥ 0.22). Nevertheless overall both groups responded similarly to the respective sprint conditions. No significant differences in step length were observed between groups for the respective condition. It is possible that continued exposure to assisted sprinting might allow the female team-sports players studied to adapt their coordination to the 'over-speed' condition and increase step frequency. It is notable that step-by-step kinematics in these sprints were easy to obtain using relatively inexpensive equipment with possibilities of direct feedback. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare barbell kinematics and muscle patterning in bench press with different loads, but with maximum effort, in young males with resistance training experience. Ten healthy experiences strength-training males (aged 27.3±5.9 years, body mass 82.8±16.6 kg, height 1.78±0.05 m, experience 7.3±4.2 years) performed maximal effort bench presses (1-2 repetitions) with loads varying from 30%, with 10% increments until 100% of 1-RM. Muscle activity of seven muscles and barbell kinematics were measured during descending and ascending phases. Average and peak upwards lifting velocity increased, while lifting time decreases with each decreasing load. In general, the maximal activation of most muscles decreases with decreasing loads, but it was not linear. No effect of loads was shown for the biceps brachii and posterior deltoid muscles. Based upon these findings, it was concluded that maximal lifting velocity may compensate for increased loads, which may allow resistancetrained males who are both healthy or in rehabilitation to avoid heavy loads but experience similar muscle activation. By decreasing the loads, the mechanical stress decreases and time to recover is reduced. Using lower loads with maximal lifting velocity may allow athletes to increase the total volume without increasing the risk of injuries. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the acute effects of using the SpeedMaker™ on step-by-step kinematics and muscle activity in 30-m sprints and if it is possible to elicit a post-activation potentiation stimulus with the SpeedMaker™ upon subsequent 30-m sprint performance. Thirteen male soccer players (age: 22.8±1.8 yr, body mass: 75.1±11.9 kg, height: 1.80±0.08 m) participated in a repeated measure and cross-over design consisting of two conditions: three normal 30-m sprints (control) and two normal 30-m sprints divided by one 30-m sprint with the SpeedMaker™ (intervention). Kinematics were measured for each step together with the peak muscle activity of the hamstrings, quadriceps and gluteus during each stride of each 30-m sprint. The main findings were that sprinting with the SpeedMaker™ increased sprint times by 1.7% compared to normal 30-m sprints. However, no occurrence of a post-activation potentiation (PAP) response was found when performing a 30-m sprint with the SpeedMaker™ prior to a normal 30-m sprint in male soccer players. Furthermore, no detectable differences in step-by-step analysis on kinematics and muscle activity were found between the sprints with and without the SpeedMaker™. Only hamstrings and gluteus activity increased per stride over 30-m. It was concluded that the SpeedMaker™ did influence sprint times, but only in a small way that kinematics and muscle activity did not change detectable. Furthermore, that the SpeedMaker™ did not elicit a PAP effect. In addition, increased hamstring and gluteus maximus activation during the 30-m sprints suggests that these muscles are very important for acceleration, and that it is likely that acute hamstring strains occur when a soccer player is close to maximal velocity, as hamstring activation is maximal at that point. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify the influence of prior knowledge of exercise duration on players’ pacing patterns during soccer small-sided games. Twenty semi-professional male soccer players participated in this study. In the first game scenario, players were not informed how long they would be required to play the small-sided game and the activity was terminated after 20 min (Unknown Condition). In the second game scenario, players were told that they would play the small-sided game for 10 min, but immediately after completing the 10-min game, they were asked to complete another 10 min (Partially Condition). In the third game scenario, players were instructed that they would play the small-sided game for 20 min and then they completed the 20-min game (Known Condition). The results presented a tendency of higher values in all performance variables in the [0′–10′] min compared with the [10′–20′] min. As the players’ previous knowledge about the tasks duration increased, the performance between two moments tended to be similar. Considering the entire 20-min game duration, the Partially Condition of the exercise was the most demanding condition. In conclusion, the knowledge of shorter durations of the exercise seems to lead to an increase of exercise duration demand, and longer exercise durations possibly tend to decrease differences between full knowledge and not knowing the exercise duration. [ABSTRACT FROM AUTHOR]

Producing comparable/greater ground reaction forces (GRFs) at faster running speeds is beneficial for sprint performance, and assisted sprint training is used to induce faster running speed conditions. This study aimed to demonstrate the characteristics of assisted sprinting at the maximal speed phase and investigate acute differences to control sprinting. Fifteen sprinters completed control and assisted (5 kg) sprints over force platforms. Assisted sprinting increased running speed (9.3% mean difference), while propulsive mean force (−4.3%) and impulse (−12.4%) decreased, suggesting that running speed improvements were caused primarily by assisted pulling force rather than improvements in anteroposterior force production of athletes. In addition, vertical mean force increased (4.2%), probably due to braking mean force (34.2%) and impulse (32.5%) increases. Magnitude of control trial maximum speed was achieved earlier (during acceleration) in assisted trials, and net anteroposterior (includes both braking and propulsive components) mean force (67.2%) and impulse (67.9%) increased at this matched speed, suggesting that assisted sprints could be used to practice producing greater GRFs at comparable speeds. Running speed improvement by pulling force was associated with contact time decreases (r = -.565), suggesting that shortening contact time may be important for effective assisted sprinting. [ABSTRACT FROM AUTHOR]

The authors' purpose was to investigate if there is a speed accuracy trade-off in soccer kicking by using instructions prioritizing velocity, accuracy, or both upon soccer kicking performance and kicking direction in experienced soccer players. In addition, kinematics were measured to investigate the eventual differences in performance. Thirteen experienced male footballers performed penalty kicks with different instructions prioritizing velocity, accuracy or both. Three-dimensional kinematics, together with maximal ball velocity and hitting accuracy, were measured on all kicks. The main findings were that when the main aim was accuracy, accuracy increased, while the velocity reduced, which supports Fitts' law (Fitts, 1954 ). In addition, kicking accuracy was higher when kicking to the contralateral side. The slower ball velocity was caused by lower segmental and in run velocities. These lower segmental velocities were mainly caused by the lower maximal knee extension and pelvis rotation during the accuracy priority kicks. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare the effects of a long warm-up (general + specific) and a short warm-up (specific) on intermediate running performance (3-minute run). Thirteen experienced endurance-trained athletes (age 23.2 ± 2.3 years, body mass 79.8 ± 8.2 kg, body height 1.82 ± 0.05 m) conducted 2 types of warmups in a crossover design with 1 week in between: a long warm-up (10 minutes, 80% maximal heart rate, and 8 x 60 m sprint with increasing intensity and 1 minute rest in between) and a short warm-up (8 x 60 m sprint with increasing intensity and 1 minute rest in between). Each warm-up was followed by a 3-minute running test on a nonmotorized treadmill. Total running distance, running velocity at each 30 seconds, heart rate, blood lactate concentration, oxygen uptake, and rate of perceived exertion were measured. No significant differences in running performance variables and physiological parameters were found between the 2 warm-up protocols, except for the rate of perceived exertion and heart rate, which were higher after the long warm-up and after the 3-minute running test compared with the short warm-up. It was concluded that a short warm-up is as effective as a long warm-up for intermediate performance. Therefore, athletes can choose for themselves if they want to include a general part in their warm-up routines, even though it would not enhance their running performance more compared with only using a short, specific warm-up. However, to increase efficiency of time for training or competition, these short, specific warm-ups should be performed instead of long warm-ups. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the acute effect of resisted sprinting upon running sprint performance. Thirty male athletes from track and field (age: 21.2±2.9 y rs, body mass: 69.8±9.8 kg, height: 1.75±0.08 m) performed two different test sessions (one day of 7x60 m runs alternating between regular and resisted sprinting and the other day 7x60 m of regular sprints) with 5 min between each run. Sled towing individually weighted to 10% of each participant's body mass was used as resistance for the resisted sprints. It was found that training with or without resistance had the same effect; there is no acute effect of resisted sprinting upon sprint performance after using resisted runs. It was concluded that resisted sprinting does not have any acute positive effect upon regular sprints of 60 m, but only a fatiguing effect. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the occurrence of the sticking region by examining how three different grip widths affect the sticking region in powerlifters’ bench press performance. It was hypothesised that the sticking region would occur at the same joint angle of the elbow and shoulder independent of grip width, indicating a poor mechanical region for vertical force production at these joint angles. Twelve male experienced powerlifters (age 27.7 ± 8.8 years, mass 91.9 ± 15.4 kg) were tested in one repetition maximum (1-RM) bench press with a narrow, medium and wide grip. Joint kinematics, timing, bar position and velocity were measured with a 3D motion capture system. All participants showed a clear sticking region with all three grip widths, but this sticking region was not found to occur at the same joint angles in all three grip widths, thereby rejecting the hypothesis that the sticking region would occur at the same joint angle of the elbow and shoulder independent of grip width. It is suggested that, due to the differences in moment arm of the barbell about the elbow joint in the sticking region, there still might be a poor mechanical region for total force production that is joint angle-specific. [ABSTRACT FROM AUTHOR]