Sprint Mechanical Characteristics of Female Soccer Players: A Retrospective Pilot Study to Examine a Novel Approach for Correction of Timing Gate Starts

The purpose of this study was to compare model estimates of linear sprint mechanical characteristics using timing gates with and without time correction. High-level female soccer players (n = 116) were evaluated on a 35-m linear sprint with splits at 5, 10, 20, 30, and 35 m. A mono-exponential function was used to model sprint mechanical metrics in three ways: without a time correction, with a fixed (+0.3 s) time correction, and with an estimated time correction. Separate repeated-measures ANOVAs compared the sprint parameter estimates between models and also the residuals between models. Differences were identified between all modeled sprint mechanical metrics; however, comparable estimates to the literature occurred when either time correction was used. Bias for both time-corrected models was reduced across all sprint distances compared to the uncorrected model. This study confirms that a time correction is warranted when using timing gates at the start line to model sprint mechanical metrics. However, determining whether fixed or estimated time corrections provide greater accuracy requires further investigation.

THE EFFECTS OF ANALOGY INSTRUCTIONS ON SPRINT PERFORMANCE AND KINEMATICS

The purpose of this study was to examine the effects of analogy and explicit instructions on 50-m sprint performance and their running kinematics. Forty-five male Physical Education undergraduates participated in this study and were randomly divided into three groups, (i.e. analogy, explicit and control). Their sprint performances were assessed using wireless timing gate while the kinematic data was assessed by Kinovea software. The analogy group received three analogies which were “run tall”, “chin to pocket” and “claw the track” throughout the intervention sessions whereas the explicit group received “keep the body posture in an upright position and aligned, head and butt not tilting outward”, “arms should maintain a 90-degree angle at the elbow throughout the upswing as well as backswing” and “the foot landing should always be on the balls of the feet”. The control group did not receive any instruction throughout the intervention period. All participants were tested again after three weeks for the post test and retention test a week after. A 3 group x 3 tests mixed design ANOVA was used to analyze the sprinting performance whereas the kinematic data was analyzed by using one way MANOVA test. Results displayed that there was no significant difference in sprint performance among the groups. However, the post hoc test showed that the analogy group improved significantly in the post test. The kinematic data showed that both intervention groups were significantly better than the control group. This study concluded that both analogy and explicit instructions resulted in better running mechanics but only the analogy group elicited better in performance. Thus, analogy instructions are suggested to be an effective method to coach sprinters.

THE CONNECTION BETWEEN THE AGILITY OF ADOLESCENT SOCCER PLAYERS AND THEIR BODY COMPOSITION

The aim of this study is to determine body composition (BC) factors that influence agility among adolescent soccer players (N=66), in U14, U16, U18 soccer teams of the Topola Sport Club. Agility tests (Dribbling test, Illinois test), Inbody 720 instrument measuring the BC, and Oxa Starter infrared timing gate instrument measuring speed the agility were used. Data are processed by the IBM SPSS Statistics 25 software. In addition to descriptive statistics, a correlation matrix analysis, linear regression and one-way analysis of variance (ANOVA) were also applied (p<0.05). A moderate correlation between agility with a ball and without a ball (r=0.595) is determined as well as between agility and BC parameters: Skeletal Muscle Mass, Intracellular Water Mass, Protein Mass, Mineral Mass (r=-0.453, -0.454, -0.453, -0.417, respectively) while the correlation between agility and Height, Mass, Body Mass Index, Right Leg Lean Mass, Left Leg Lean Mass, Extracellular Water Mass is less than moderate (r=-0.318, -0.329, -0.276, -0.332, -0.330, -0.374, respectively). A slight correlation is determined between agility with a ball and BC variables. No correlation was determined between Agility and Body Fat Mass. The influence of BC on agility is lower than expected. Using the scientific based approach and measurements, a complex exercise plan can be made for players and in this way young soccer players can be trained by using tailor-made and post-specified coaching methods.

Pengembangan prototipe sistem track timer untuk pengukuran kecepatan secara otomatis pada sprint 60-meter

Saat ini sedang berkembang pencatatan waktu otomatis yang dijual oleh beberapa perusahan perlatan olahraga ternama seperti. Namun sayangnya, harga perangkat tersebut sangatlah mahal, dan membuat setiap pelatih ataupun praktisi olahraga terkendala untuk mendapatkannya. Karena fakta dan permasalahan tersebut, maka penelitian ini bertujuan untuk mengembangkan prototipe sistem pencatatan waktu untuk pengukuran kecepatan secara otomatis pada sprint 60-meter, dengan menggunakan perangkat sederhana dengan harga yang murah, namun memiliki tingkat presisi dan akurasi yang baik. Penelitian ini menggunakan metode penelitian research and development, dimana dalam proses pengembangan dan pembuatan pencatatan waktu otomatis, penelitian ini mengambil contoh dari timing gate yang sudah divalidasi sebelumnya. Dalam penelitian ini, kami juga sudah melakukan uji coba kepada 12 atlet sprinter (tinggi badan 172.8 ± 9.31, berat badan 61.05 ± 6.90, BMI 20.38 ± 0.87) terkait kegunaan alat tersebut. Rata-rata kecepatan lari seluruh subjek pada pos 10-meter adalah 2.44 ± 0.23 detik, pos 20-meter adalah 3.71 ± 0.18 detik, pos 30-meter adalah 4.75 ± 0.22 detik, pos 40-meter adalah 6.39 ± 0.31 detik, 50-meter adalah 7.65 ± 0.41 detik, dan 60-meter adalah 9.12 ± 0.49 detik. Penelitian research and development terkait pengembangan pencatatan waktu otomatis dalam penelitian ini, menunjukkan bahwa pencatatan waktu otomatis dapat dibuat dengan harga ekonomis, dan dapat digunakan untuk mengukur kecepatan lari 60-meter. Development of track timer prototype system for automatic speed measurement on 60-meter sprints AbstractCurrently, automatic track timers are being sold by several well-known sports equipment companies. Unfortunately, the price of the device is very expensive and makes every coach or practitioner constrained to get it. Because of these facts and problems, this research was aimed to develop a prototype track timer system for automatic speed measurement on a 60-meter sprint, using a simple device at a low price, but has a good level of precision and accuracy. This study used to research and development research methods, wherein the process of developing and manufacturing automatic track timers, this study takes the example of a timing gate that has been validated before. In this study, we have also tested 12 sprinters (height 172.8 ± 9.31, weight 61.05 ± 6.90, BMI 20.38 ± 0.87) related to the use of the tools. The average running speed of all subjects on a 10-meter post is 2.44 ± 0.23 seconds, a 20-meter post is 3.71 ± 0.18 seconds, a 30-meter post is 4.75 ± 0.22 seconds, a 40-meter post is 6.39 ± 0.31 seconds, 50- The meter is 7.65 ± 0.41 seconds, and the 60-meter is 9.12 ± 0.49 seconds. This research shows that track timers can be made at economical prices, and can be used to measure 60-meter running speed.

Sprint and Change of Direction Performances on Three Different Futsal Playing Surfaces

This study was conducted to clarify the differences in sprint and change of direction performances on different futsal flooring systems (area-elastic (AE) vs. combined-elastic (CE)). Eight recreational athletes were recruited to perform the 505-agility test on three different EN 14904-certified futsal playing surfaces (AE, CE1 and CE2). All participants wore an identical footwear during the test. Timing-gate systems were utilized to record the time of 5-m sprint run-up and the change of direction components from the agility test. Participants were also requested to evaluate the perceived shoe-surface overall traction performance after each trial. The differences of performance across all surfaces were analyzed by one-way ANOVA repeated measures (p < 0.05). Results revealed that there was significant difference in change of direction performance between CE1 and CE2 surfaces (p = 0.04). It was also found that the mean score of the perceived traction performance evaluated by the participants were significantly different across all surfaces (p < 0.05).

Sprint Mechanical Properties of Female and Different Aged Male Top-Level German Soccer Players

This study compared the sprint mechanical properties of female and different aged male top-level soccer players. A total of 14 adult females (FEM) and 115 different aged male field players, competing at German top levels, participated in this study. The males belonged to teams of under 12, 13, 14, 15, 17, 19, and 23 years (U 12–23) and professionals (PRO). All players were tested for a 30 m linear sprint. From timing gate derived sprint times, force-velocity and power-velocity relationships, as well as theoretical maximum running velocity, force, and power data were computed by an inverse dynamic approach applied to the center of mass. The approach was optimized for taking the starting time into account, which is a progress in the present research field, when aiming to compute sprint mechanical properties by different methodological approaches under field conditions. Sprint mechanical properties of FEM were lower than those of PRO. Compared to other age groups, sprint mechanical properties of FEM were similar to those of U 14 and U 15. An increase in sprint mechanical properties was found from U 12 to U 17. The study shows that sprint mechanical properties differ according to gender and age in top-level soccer players.

Validity of 10-HZ GPS and Timing Gates for Assessing Maximum Velocity in Professional Rugby Union Players

Purpose:The purpose of this study was to investigate the validity of timing gates and 10-Hz global positioning systems (GPS) units (Catapult Optimeye S5) against a criterion measure (50-Hz radar gun) for assessing maximum sprint velocity (Vmax).Methods:Nine male professional rugby union players performed 3 maximal 40-m sprints with 3 min rest between efforts with Vmax assessed simultaneously via timing gates, 10-Hz GPSOpen (Openfield software), GPSSprint (Sprint software), and radar gun. Eight players wore 3 GPS units, while 1 wore a single unit during each sprint.Results:When compared with the radar gun, mean biases for GPSOpen, GPSSprint, and timing gates were trivial, small, and small, respectively. The typical error of the estimate (TEE) was small for timing gate and GPSOpen while moderate for GPSSprint. Correlations with radar gun were nearly perfect for all measures. Mean bias, TEE, and correlations between GPS units were trivial, small, and nearly perfect, respectively, while a small TEE existed when GPSOpenfield was compared with GPSSprint.Conclusion:Based on these findings, both 10-Hz GPS and timing gates provide valid measures of 40-m Vmax assessment compared with a radar gun. However, as error did exist between measures, the same testing protocol should be used when assessing 40-m Vmax over time. Furthermore, in light of the above results, it is recommended that when assessing changes in GPS-derived Vmax over time, practitioners should use the same unit for each player and perform the analysis with the same software, preferably Catapult Openfield.

Correction Factors for Photocell Sprint Timing With Flying Start

Purpose:A review of published studies monitoring sprint performance reveals considerable variation in start distance behind the initial timing gate. The aim of the current study was to generate correction factors across varying flying-start distances used in sprint testing with photocells.Methods:Forty-four well-trained junior soccer players (age 18.2 ± 1.0 y, height 175 ± 8 cm, body mass 68.4 ± 8.9 kg) performed sprint testing on an indoor sprint track. They were allocated to 3 groups based on sprintperformance level. Times for 10- and 200-m sprint with foot placement ranging from 0.5 to 15 m back from the initial timing gate were recorded twice for each athlete.Results:Correction-factor equation coefficients were generated for each of the 3 analyzed groups derived from the phase-decay equation y = (y0 − PL) × exp(−k × x) + PL, where y = time difference (0.5-m flying start as reference), x = flying-start distance, y0 is the y value when time is zero, PL (plateau) is the y value at infinite times, and k is the rate constant, expressed in reciprocal of the x-axis time units; if x is in seconds, then k is expressed in inverse seconds. R2 was ≥.998 across all athlete groups and sprint distances, demonstrating excellent goodness of fit. Within-group time differences were significant (P < .05) across all flying-start distance checkpoints for all groups. Between-groups time-saving differences up to 0.04 s were observed between the fastest and the slowest groups (P < .05).Conclusions:Small changes in flying-start distances can cause time differences larger than the typical gains made from specific training, or even the difference between the fastest and slowest elite team-sport athletes. The presented correction factors should facilitate more meaningful comparisons of published sprint-performance results.

Planned and Reactive Agility Performance in Semiprofessional and Amateur Basketball Players

Context:Research indicates that planned and reactive agility are different athletic skills. These skills have not been adequately assessed in male basketball players.Purpose:To define whether 10-m-sprint performance and planned and reactive agility measured by the Y-shaped agility test can discriminate between semiprofessional and amateur basketball players.Methods:Ten semiprofessional and 10 amateur basketball players completed 10-m sprints and planned- and reactive-agility tests. The Y-shaped agility test involved subjects sprinting 5 m through a trigger timing gate, followed by a 45° cut and 5-m sprint to the left or right through a target gate. In the planned condition, subjects knew the cut direction. For reactive trials, subjects visually scanned to find the illuminated gate. A 1-way analysis of variance (P < .05) determined between-groups differences. Data were pooled (N = 20) for a correlation analysis (P < .05).Results:The reactive tests differentiated between the groups; semiprofessional players were 6% faster for the reactive left (P = .036) and right (P = .029) cuts. The strongest correlations were between the 10-m sprints and planned-agility tests (r = .590–.860). The reactive left cut did not correlate with the planned tests. The reactive right cut moderately correlated with the 10-m sprint and planned right cut (r = .487–.485).Conclusions:The results reemphasized that planned and reactive agility are separate physical qualities. Reactive agility discriminated between the semiprofessional and amateur basketball players; planned agility did not. To distinguish between male basketball players of different ability levels, agility tests should include a perceptual and decision-making component.