RELATIONSHIP BETWEEN ISOKINETIC STRENGTH, VERTICAL JUMP, SPRINT SPEED, AGILITY AND YO-YO INTERMITTENT RECOVERY TEST PERFORMANCE IN SOCCER PLAYERS

The current study investigated the relationship between isokinetic knee strength, jump performance, agility, linear and repeated sprinting capacity and Yo-Yo IR1 test performance and the fatigue indices of some of these variables in semi-professional soccer players. Twenty semi-professional soccer players participated in this study, performing 6 tests: bilateral concentric isokinetic strength tests of the knee extensors and flexors (60◦.s-1 and 300◦.s-1), jump tests (countermovement, squat and repeated jumping), linear sprints (10 and 30 m), agility (Illinois test), Bangsbo repeated sprints (7 x 34.2 m), and Yo-Yo IR1 tests. While no isokinetic variables were significantly correlated with field test results, some jump test results correlated with AgiWB, 10- and 30-m sprint times, RSTMEAN and FIRS. Furthermore, the knee isokinetic strength (60◦.s-1 and 300◦.s-1) indices and jump capacities demonstrated moderate to strong relationships with each other. In addition, AgiWB correlated with the 10-m sprint times and RSTMEAN, 30-m linear sprint times correlated with 10-m sprint times and AgiWB, and FIRS and RSTMEAN correlated with the Yo-Yo IR1 test results. The results suggest that power output during CMJ and RJ tests and not isokinetic knee strength are informative in determining field conditioning parameters for semi-professional soccer players.  Article visualizations

THE EVALUATION OF GROUND REACTION FORCES DURING TWO DIFFERENT SOCCER THROW-IN TECHNIQUES: A PRELIMINARY STUDY

The purpose of this study was to examine the differences in Ground Reaction Forces (GRF) between standing and running soccer throw-in. Six male amateur soccer players participated in the current study. All data are expressed as mean±SD. The longer distance was observed in the running throw-in than the standing throw-in. The standing throw-in showed higher values at Vertical (Fz) GRF during back swing, forward swing and release phases. However, that of the running throw-in during follow through phase was higher than that of the standing throw-in. As a result, the longer throwing distance in the running throw-in can be explained that the players spend shorter time in all phases at running throw-in than they did in the standing throw-in. This might causes efficient energy transfer from proximal to distal segment during the running throw-in

EFFECTS OF 8-WEEKS WHOLE BODY VIBRATION TRAINING ON SOME MARKERS 06 TENNIS PERFORMANCE

The aim of the current study was to investigate the effects of Whole Body Vibration (WBV) training on some tennis performance parameters like International Tennis Numbr (ITN) scores, serve speed, reactive agility (with and without racket), 5171, 10m, 20m sprint and isokinetic strength values. 19 tennis players (training group: 9, control group: 10) participated in the research as volunteers. All the selectd parameters were measured before and after the training protocol. While control group was following regular tennis training, intervention group practiced WBV training for eight weeks (3 times a week, 1 level up for every fortnight, 15-20 mins per section). Consequently, it has been revealed that WBV training made an increase in selected performance parameters of athletes

Comparing the maximal aerobic speed assessed with laboratory and field tests in soccer players

Investigating the differences between field tests used in practice and laboratory tests is important for accurate performance assessment in soccer players. Therefore, the aim of the study was to compare the maximal aerobic speed (MAS) obtained from the VAM-EVAL and Yo-Yo intermittent recovery test (YYIR1), with an incremental (1km.h-1 per min) treadmill test in soccer players. Eighteen amateur male soccer players, were evaluated with the following tests: a) a treadmill test to directly determine values of maximal oxygen uptake (VO2max) and MAS (Treadmill); b) an indirect VAM-EVAL Test; c) an indirect YYIR1. The results demonstrated that the last speed, distance, and test duration values are significantly different among the tests . (p<0.05)]. The highest MAS value was recorded during the treadmill test (17.10 ± 1.38 km.h-1) which was significantly different from YYIR1 and VAM-EVAL tests (15.82 ± 0.66 and 14.33 ± 0.69 km.h-1, respectively; p<0.001). The analysis also showed that treadmill MAS value was significantly correlated with YYIR1 MAS (r = 0.656) and VAM-EVAL MAS values (r = 0.625), also YYIR1 MAS value was significantly correlated with VAM-EVAL MAS value (r = 0.662). It was concluded that the MAS and the VO2max values are significantly different among YYIR1, VAM-EVAL and selected treadmill protocol, and support the idea that they should not be used interchangeably. From a practical perspective, MAS seems to be more important for coaches than VO2max. Both laboratory and field tests can be useful for assessing MAS; however, field tests should be preferred for training purposes

The effect of isolated or combined small-sided games and speed endurance training on physical performance parameters in young soccer players

The purpose of this study was to investigate the effects of six weeks of small-sided games (SSG), speed endurance (SER) and combined SSG and SER (CT) training programs on sprint, repeated sprint, Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) and level 2 (Yo-Yo IR2) performance in young soccer players. Forty-one elite young soccer players (body height: 174.0 ± 7.5 cm, body weight: 59.7 ± 9.5 kg, age: 14.6 ± 0.5 years, training age: 7.4 ± 0.6 years) underwent anthropometric measurements before performing 10m and 30m sprint tests, repeated sprint tests, and Yo-Yo IR1 and Yo-Yo IR2. The players were then divided into four groups: the SSG group (SSG; n=11), the SER group (SER; n=10), the CT group (CT; n=11), and the control group (CG; n=9). All groups performed training for six weeks on two days out of the five training days the participants were undertaking. There was a statistically significant increase in the Yo-Yo IR1 and Yo-Yo IR2 test performances of players in SSG, SER and CT groups (p&lt;.05). In addition, players in these groups showed significantly higher percentage increases in Yo-Yo IR2 test performance compared to the CG. The CT group also had a statistically significant increase in Yo-Yo IR1 test performance compared to the CG (p&lt;.05). In conclusion, while this study shows that SSG and SER training can be used for physical performance development in isolation or in combination, coaches and sports scientists are advised to choose combined training to use training time more efficiently

KINETIC AND KINEMATIC ANALYSIS OF RECURVE ARCHERY SHOOTING TECHNIQUE

The study investigated shooting techniques of the archers with kinetic and kinematic methods. Twenty-seven archers of different skill levels have been involved into the current study to investigate both muscular activation strategies of nine muscles and some kinematic data on drawing hand side. A statistical significant difference (p0.05) in the time-dependent exchange values of the angle of the joints, a difference was detected in the graphical sense. Elite archers use distal muscles less but proximal and axial muscles more, and mid-level and novice archers use distal muscles more to pull the bowstring. This was interpreted to be the most important factor affecting the horizontal oscillation (lateral diflection) of bowstring

DEVELOPMENTAL DIFFERENCES OF KINEMATIC AND MUSCULAR ACTIVATION PATTERNS IN INSTEP SOCCER KICK

The aim of the study was to evaluate kinematic and muscular activation differences amongst different age groups of soccer players. Thirty male youth soccer players were divided into 3 groups according to their age (age 12-13; age 14-15; age 16-17). There were significant differences in ball velocities and isokinetic strength values amongst groups. Angular and linear velocities of hip, knee, ankle and toe were also significantly different (

PHYSIOLOGIC RESPONSES OF DIFFERENT AEROBIC LEVEL ATHLETES TO ALTITUDE TRAINING AND OPTIMUM ALTITUDE AND EXPOSING TIME

This study has indicated that the effect of altitude training on endurance performance of elite and non-elite athletes and the optimum altitude and exposing time. In many research it has been proved that the threshold should be 2500 m and 3-4 weeks or above in order that altitude training show effect on athletes. However, changes regarding effect of the training above this threshold showed differences on elite athletes who compete in different sports, in some research endurance parameters improve, while in some research it did not. In this sense, at the basic of this differences it is important that the natural endurance threshold of the athletes and where the athletes reached of this threshold before altitude training

The Effect of Kick Type on the Relationship between Kicking Leg Muscle Activation and Ball Velocity

This study aimed to identify the effects of different kick types on the relationship between kicking leg muscle activation and ball velocity. The muscle activation of selected knee extensor and flexor muscles of 10 amateur soccer players were measured using electromyography during the performance of six maximal soccer kick types. The highest ball velocity was achieved by the instep kick (96.2 km/hr-1), followed by the lofted kick, the inside curve kick, the outside kick, the outside curve kick, and finally the inside kick (81.3 km/hr-1). There were significant positive correlations between muscle activation and ball velocity for the vastus lateralis and lofted (0.765), inside curve (0.792) and instep kicks (0.788), and for the gastrocnemious with the outside kick (0.796). Non-significant correlations between muscle activation and ball velocity exhibited a trend such that they were positive for the vastus medialis and vastus lateralis but negative for the biceps femoris and gastrocnemious for inside-foot-dominated kicks, while this trend was reversed for outside-foot-dominated kicks. According to results, the noted trends can be explained by the change in muscle activation patterns required to orientate the foot for each type of kick; this has implications for players’ training activities

Effects of functional balance training on static and dynamic balance performance of adolescent soccer players

Aim: The purpose of the study was to investigate the effects of functional balance training on static and dynamic balance performance, kicking velocity and to define the relationship between balance ability and kicking velocity of adolescent soccer players.Material and Methods: Sixteen male players randomly divided into 2 groups (Control Group: age 14,23±0,44; Training Group: age 14,31±0,48). While the control group (n=8) followed regular soccer training, the training group (n=8) performed a functional balance training program additively. The balance training was performed on both stable ground and unstable surface (BOSU ball). SportKat2000 system were used to elicit static and dynamic balance scores of right, left and both leg stance of the soccer players.Results: All static balance variables (dominant, non-dominant and both leg) of training group and one variable (non-dominant leg) of control group showed statistically significant differences (p&lt;0,05) after training. Dynamic dominant leg scores of training group and dynamic non-dominant leg scores of control group were statistically significant as well. Ball velocity of training group improved %5.6 in training group and %3.7 in control group. Besides, dominant leg ball velocity correlated with dynamic dominant (p&lt;0.05; r: -0,767) and both leg (p&lt;0.05; r: -0,787) balance ability for training group. Non-dominant ball velocity also correlated with dynamic dominant (p&lt;0.01; r: -0,844) and dynamic non-dominant leg (p&lt;0.05; r: -0,778) balance ability in training group after training period.Conclusion: As a conclusion, functional balance training performed three times in a week positively affect the balance ability and kicking performance of adolescent soccer players