Change Of Direction Speed Test Research Articles

Concurrent validity of single- and dual-beam timing systems for linear and change of direction speed testing in youth soccer players

This study investigates the concurrent validity of the Sportreact single-beam timing system with a standard dual-beam system for the evaluation of linear and change of direction speed. Forty-two youth soccer players (age = 12.9 ± 1.1 years) performed linear sprints (10 and 30 m splits) and 505 Agility Test. The times were measured by both systems simultaneously. The single-beam timing system was set at a height of 64 cm from the ground, while the dual-beam system was set at 67 and 90 cm for the lower and upper beam, respectively. The results showed very high intraclass correlation coefficients for the 10 m sprint (ICC (95% CI); 0.95 (0.93–0.98)), 30 m sprint (0.99 (0.98–0.99)), and 505 Agility Test (0.98 (0.98–0.99)), with a low typical error of estimates (TEEs (%) = 2.16%, 1.12%, and 1.05%, respectively). However, TEE of 0.046 s in the 10 m sprint test overlapped the smallest worthwhile change (≈0.030 s). Bland-Altman analyses showed 95% LoA ranging from −0.086 to 0.093 s for the 10 m sprint, −0.115 to 0.106 s for the 30 m sprint, and −0.055 to 0.049 for 505 agility tests. The Sportreact single-beam timing system provides a useful tool for linear sprint (≥30 m) and change of direction speed tests only when considering heterogeneous groups but not individual athletes. However, this system should not be used interchangeably with a dual-beam systems for the assessment of linear and change of direction sprint tests in youth team sport players.

Evolution of the Correlation Between Body Mass Index (BMI) and Agility of Primary School Students in North-Eastern Romania

Interacting with children's cognitive processes and mental health status, body mass index (BMI) could be analyzed in relation to motor performance. This study aims to analyse the relationship between BMI and agility of primary school students in the northeast of Romania. Hypothesis testing was done by analyzing data obtained from 3250 pupils (1605 girls and 1645 boys) aged 6 to 11 years old from the North-East of Romania. BMI was calculated based on height and weight, as well as agility through the 505 change of direction speed test. The sample was divided according to gender and age, and the differences and correlations were analysed. We assumed that our sample has a significant correlation of BMI with agility and that its strength increases with age, based on neural maturation. Children's results showed gender- and age-determined differences in anthropometric as well as motor skills. The development of Romanian girls and boys differs punctually at this stage, with the two genders having close BMI values at age 11. The time to complete the 505 test is close at age 6, with boys performing better by age 11. The correlation between BMI and agility has weak strength in the 6-11 years age group of Romanian students. It is significant in girls at 9 (r = 0.20) and 10 years (r = 0.15), and in boys from 7 (r = 0.20) to 10 years (r = 0.22). The data partially confirm our hypothesis, with the correlation existing in the 7-10 years age range, its strength having a fluctuating evolution. At 11 years the link between BMI and agility ceases to exist.

In pursuit of precısion: assessing the impact of physical attributes on change of direction speed ın women's cricket

Cricket demands a unique blend of athleticism, strategy, and precision, with physical fitness crucial in achieving sports excellence. While previous research has highlighted the importance of physical attributes such as speed, explosive power, and agility, the complex interactions between these factors about change of direction speed (CODS) still need to be better understood. This study investigated the relationship between CODS and key physical measures among female cricket players, providing insights into the factors influencing athletic performance in cricket. Thirty female cricketers (aged 16-26 years) participated in the study, undergoing assessments of CODS, speed, vertical jump, and broad jump. Statistical analyses, including Pearson correlation coefficients, multiple regression analysis, and ANOVA, were employed to examine the relationships between these physical measures and CODS. Reliability was deemed to be poor (<0.3), moderate (0.4<0.6), and strong (0.7≤) based on prior research. Significant positive correlations were observed between agility and acceleration and maximal speed tests, underscoring the importance of speed in cricket performance. Furthermore, moderate to strong negative correlations were found between CODS and explosive lower body power tests, highlighting the significance of lower body explosiveness for rapid directional shifts in cricket. Regression analysis revealed that speed, broad jump, and vertical jump collectively contributed to a strong predictive model for agility. Enhancing speed, explosive power, and agility through targeted training interventions could improve cricket players' on-field performance and competitive edge. Overall, this study contributes to understanding the complex interactions between physical attributes and cricket performance, offering practical insights for player development and strategic improvement. Key Words: Change of Direction Speed; Physical Attributes; Explosive Power; Agility

Determination of change of direction deficit thresholds across a spectrum of angles in basketball players

ABSTRACT Change of direction deficit (CODD) offers valuable insights into a player’s balance between linear and multidirectional speed. However, there are still no established reference values for CODD. The objectives of this study were to determine CODD thresholds for various change of direction angles in basketball players according to gender and analyse the relationships between CODD and execution time in speed tests. One hundred and thirty basketball players (46% female; age: 23.7 ± 5.29 years; height: 189.1 ± 11.1 cm; body mass: 84.3 ± 15.7 kg) undertook 10-m linear and change of direction speed test at 45º, 90º and 180º. A k-means cluster analysis was conducted to standardise CODD thresholds and a one-way analysis of variance to identify the differences between clusters. The results revealed angulation-specific CODD thresholds, ranging from 3% to 8%, 17% to 25% and 43% to 51% for 45º, 90º and 180º cutting angles, respectively for the pooled sample. Furthermore, differences inter-clusters (p < 0.05) were observed for execution time at all cutting angles for both genders. Therefore, strength and conditioning coaches are encouraged to assess CODD as a highly valid variable for evaluating change of direction performance and to use current CODD thresholds to tailor training programmes according to each athlete’s needs.

Effects of six-week stroboscopic training program on visuomotor reaction speed in goal-directed movements in young volleyball players: a study focusing on agility performance

BackgroundIn team sports, deficits in visuomotor reaction speed are considered a significant and modifiable risk factor that can lead to decreased performance and an increased risk of injuries. Thus, identifying effective methods to enhance visuomotor abilities is crucial. The main objective of this research was to investigate the impact of a six-week stroboscopic intervention on visuomotor reaction speed in goal-directed specific movements based on agility among young volleyball players. Additionally, the study aimed to explore the impact of saccade dynamics on visuomotor reaction speed performance throughout the experiment.MethodsThere were 50 athletes (26 males and 24 females) with an average age of 16.5 years (± 0.6) who participated in this study. Over a six-week training period, athletes performed volleyball-specific training either wearing stroboscopic glasses (intervention) or under normal visual conditions (control). Prior to and after the training period, the agility tests based on change-of-direction speed (CODS) and reactive agility (RA) were used to identify visuomotor reaction speed performance. To measure agility performance a five-repetition shuttle run to gates was conducted. The REAC-INDEX, which represents visuomotor reaction speed, was analyzed as the resulting difference between the CODS test and the RA test. To elicit saccadic dynamics, a laboratory visual search task was performed.ResultsA significant GROUP×TIME interaction was observed for the REAC-INDEX (p = 0.012, ηp2 = 0.13). ANCOVA analyses revealed significant GROUP differences, indicating improved post-training REAC-INDEX results (p = 0.004, d = 0.87), regardless of gender. Training-induced modulations in saccade acceleration did not reach significance, but a significant relationship was observed between changes in saccade acceleration and changes in the REAC-INDEX (r = -0.281, p = 0.048), indicating that higher performance gains following training were associated with a stronger increase in saccade acceleration.ConclusionsThis study demonstrates that stroboscopic training effectively enhances visuomotor reaction speed in goal-directed movements based on agility. Furthermore, visuomotor reaction speed gains could potentially be mediated by saccade dynamics. These findings provide valuable insights into the effectiveness of stroboscopic eyewear for training sport-specific visuomotor skills among young volleyball players.

Assessing Limb Dominance and Interlimb Asymmetries Over Multiple Angles During Change of Direction Speed Tests in Basketball Players.

Gonzalo-Skok, O, Dos' Santos, T, and Bishop, C. Assessing limb dominance and interlimb asymmetries over multiple angles during change of direction speed tests in basketball players. J Strength Cond Res 37(12): 2423-2430, 2023-The aims of this study were to establish whether directional dominance is displayed during change of direction (COD) tasks across various angles, to determine the angle-variation data for the asymmetry magnitude and direction, and to analyze the relationships in COD performance (completion time and COD deficit) across tasks. Twenty-four young (U-16 to U-20), highly trained male basketball players performed a 10-m linear sprint test and four 10-m COD tests (45°, 90°, 135°, and 180°) in left and right directions. Change of direction performance was determined via total times and COD deficit, and asymmetry comparisons were made between faster and slower directions and dominant leg (DL) (i.e., first step leg in lay-up) and nondominant leg (NDL). No significant differences (p > 0.05) were found between DL and NDL for any task excluding 45° COD (p < 0.05, effect size [ES] = 0.44-0.78), but significant differences were established between faster and slower sides for all angles (p < 0.05, ES = 0.70-1.28). Levels of the agreement in directional dominance during COD tasks were generally poor to slight (k = -0.14 to 0.14), excluding a fair agreement between COD45 and COD90 (k = 0.34). Correlations between COD total times and COD deficits between angles were moderate to very large (r = 0.32 to 0.81) and moderate to large (r = -0.30 to 0.55), respectively. Players displayed superior COD performance in a particular direction across various angles. This directional dominance is not necessarily consistent between angles, thus highlighting the angle-dependent nature of COD performance. Consequently, practitioners should investigate multiple angles and directions to create a COD angle profile for their athletes.

Unleashing potential and optimizing adolescent roller skating performance through a structured exercise program – a randomized controlled trial

BackgroundThe intricate nature of an athlete's abilities evolves dynamically with the enhancement of motor skills. Hence the study sought to investigate the impact of a tailored four-week exercise program`encompassing exercises focused on balance, agility, and speed. The primary objective was to determine how this exercise program influences both the roller skating talent and overall physical fitness proficiency in young male roller skaters.MethodsThirty male participants (age 11–14 years) enrolled in the school skating team were recruited. The participants were randomized into either an experimental group [n = 15], performing a short-term exercise program, or a control group [n = 15], involved in the physical education classes for eight sessions over four weeks. The primary outcome measure, the skating performance, was measured by the linear speed test (LST). The secondary outcomes, i.e., balance, agility, and speed, were evaluated using the star excursion balance test (SEBT), agility t-test (ATT), and arrowhead change of direction speed test (ACDT). SEBT was assessed in 8 directions. The study was registered with the Clinical Trials Registry India (TRN: CTRI/2018/09/015713) before the recruitment of the participants on 14/09/2018.ResultsThe results showed that LST, ATT, and ACDT improved significantly (p < 0.05) in both groups, however, greater (p < 0.05) improvement was observed in the experimental group (Cohen’s d 0.8 to 1.3). Regarding SEBT, improvement was observed in a few directions only in both groups. However, no significant difference was observed between both groups in SEBT measurements.ConclusionsA short-term structured exercise program consisting of balance, agility, and speed exercises significantly improved the talent of skating, agility, and speed compared to physical education classes activities in young male roller skaters. The study highlights the potential of targeted training interventions to enhance athletic performance in this population.

Validity, Reliability, and Sensitivity of Mobile Applications to Assess Change of Direction Speed.

This study aimed to assess the validity, reliability, and sensitivity of mobile applications for assessing change-of-direction speed (CODS) performance. Thirty college athletes performed two Illinois CODS tests during one session. Assessments were carried out simultaneously using six devices (the CODTimer app, Seconds Count app, StopwatchCamera app, two analog stopwatches, and timing gates). Validity analyses included Pearson's product-moment correlation analysis, a linear regression model, and Bland-Altman plots. Reliability analyses included the intraclass correlation coefficient (ICC), the coefficient of variation (CV%), and the paired-sample t test. Sensitivity analyses included the typical error and smallest worthwhile change (SWC). The results showed that validity, reliability, and sensitivity values were higher for the CODTimer app (r = 0.99, R2 = 0.99, mean bias = -0.03 ± 0.10, CV% = 3.21, ICC = 0.89, SWC rating: good, p = 0.84) and the Seconds Count app (r = 0.99, R2 = 0.99, mean bias = -0.03 ± 0.08, CV% = 3.28, ICC = 0.88, SWC rating: good, p = 0.84) relative to the StopwatchCamera app (r = 0.98, R2 = 0.97, mean bias = -0.11 ± 0.22, CV% = 3.43, ICC = 0.86, SWC rating: marginal, p = 0.10), Analog Stopwatch 1 (r = 0.98, R2 = 0.96, mean bias = -0.09 ± 0.42, CV% = 2.95, ICC = 0.90, SWC rating: good, p = 0.91), and Analog Stopwatch 2 (r = 0.99, R2 = 0.97, mean bias = -0.12 ± 0.88, CV% = 3.51, ICC = 0.87, SWC rating: marginal, p = 0.96). In conclusion, compared to timing gates, the CODTimer app and Seconds Count app provided lower measurement bias and higher sensitivity for assessing CODS performance.

Effects of a Short-Term Detraining Period on the Strength Deficit and Functional Performance of Highly Trained Soccer Players.

Loturco, I, Grazioli, R, Veeck, F, Nakamura, FY, Inácio, M, Schons, P, Preissler, A, Pinto, RS, Pereira, LA, McGuigan, MR, and Cadore, EL. Effects of a short-term detraining period on the strength deficit and functional performance of highly trained soccer players. J Strength Cond Res 37(10): 2058-2063, 2023-The aim of this study was to examine the effects of a 4-week detraining period on the neuromuscular performance of highly trained soccer players. Pre and post detraining, 18 adult soccer players (age: 27 ± 4.9 years; height: 180.2 ± 7.1 cm; body mass [BM]: 78.9 ± 7.6 kg) performed vertical jumps, 20-m linear sprints, curve sprint and change of direction speed tests, and a progressive loading test in the half-squat exercise with loads corresponding to 50, 100, and 150% of the players' BM to assess the peak-force (PF), mean power (MP), and strength-deficit (SDef). Pre and post differences in the variables of interest were analyzed using paired t -tests and effect sizes (ES). No significant changes were detected for vertical jumping height and sprint times. Higher PF at 50 and 100% BM and lower SDef were shown when comparing pre- and postassessments (ES = 0.66, 0.68, 0.55; p = 0.018, 0.016, and 0.046, respectively). The MP at 50 and 100% BM increased significantly after the detraining phase (ES = 0.56, 0.82; p = 0.049 and 0.007, respectively). The results indicate that these athletes were able to maintain and achieve satisfactory levels of performance after a short period of training cessation. Interestingly, some strength- and power-derived parameters improved significantly after short-term detraining, which may have important implications for training programs aimed at maximizing speed and power performance. It is recommended that coaches test their players not only at the beginning but also at the end of the season, to better evaluate variations in performance and thus create more efficient and tailored training strategies.

Change of Direction Deficit: A Promising Method to Measure a Change of Direction Ability in Adolescent Basketball Players.

The aims of this study were to determine the relationship between vertical jumping performance, linear speed, change of direction speed (CODs) time and the COD deficit (CODD) in adolescent basketball players and to analyze the CODD between faster and slower players based on linear speed performance. Thirty-eight male basketball players (age: 15.47 ± 0.51 years; body height: 185.19 ± 5.67 cm; body mass: 71.87 ± 7.29 kg) completed countermovement jumps (CMJ) with and without an arm swing, squat jumps (SJs), linear sprints at 20 m with split times at 5 and 10 m, the pro-agility test and the zig-zag tests. Furthermore, the CODD was calculated as the difference between the 20 m linear speed result and CODs time in both COD tests. Pearson and Spearman analyses were used to determine the correlations between power-speed-related variables and the CODD. Moreover, independent t-tests and Cohen's d effect size (ES) were used to analyze the differences between the faster and slower players in the CODD. Moderate to strong significant negative correlations were observed between the CODD in the pro-agility test and linear speed at 5 m, 10 m, and 20 m (r = -0.55 to -0.46), while moderate negative significant correlation was found between the zig-zag CODD and SJs (r = -0.37) as well as small positive significant correlation between the CODD in the zig-zag test and the eccentric utilization ratio (EUR) (r = 0.23). Additionally, faster basketball players displayed significantly higher CODD values performing the pro-agility test. In summary, these findings underline the complexity of COD performance and the importance of remodeling traditional training programs in basketball players.

Contributing Factors to Sensorimotor Adaptability in Reactive Agility Performance in Youth Athletes.

Sensorimotor adaptability facilitates adjusting behaviour for changing environmental stimuli to maintain appropriate goal-directed motor performance. Its effectiveness is associated with perceptual-cognitive modulation. As the factors affecting it are still not completely known, the aim of our study was therefore to analyse the association between selected variables (demographic, training, anthropometric, genetic) and sensorimotor adaptation in reactive agility tasks in youth team-sport athletes. The study group consisted of 85 youth athletes (aged 12.61 ± 0.98 years). Based on an initial evaluation, participants were divided into faster and slower agility groups. The resultant differences between change of direction speed tests and reactive agility tests provided the REAC-INDEX as a dependent variable. The independent variables were as follows: gender, calendar age, body mass, height, BMI, maturity offset, training status and the BDNF rs6265 polymorphism. Multiple linear regression showed that the maturity offset (ß = 0.269; p = 0.012) and calendar age (ß = -0.411; p < 0.001) significantly contributed to the REAC-INDEX of all participants (R2 = 0.13). In the slower group, the c.196G BDNF allele had a significant influence (ß = -0.140; p = 0.044) on the REAC-INDEX. The best predictive model comprised female gender (ß = 0.799; p < 0.001), maturity offset (ß = -0.586; p < 0.001) and training experience (ß = -0.225; p = 0.009), contributing to 49% of RA variance. Sensorimotor adaptability is mainly dependent on gender and age, and can be improved through systematic sports training. The BDNF rs6265 polymorphism may be considered a contributing factor to SA variability in the initial stages of training, although polymorphism-related differences blurred as the effect of participation in sports training increased.

Investigating Reliability and Validity of the Tests of Change of Direction and Reactive Agility in Patients After Knee Surgery

Agility is one of the key performance factors important for prevention of falls. There is a lack of tests applicable for testing agility in untrained, older and clinical populations. The aim of tis research was to investigate the reliability and validity of the newly-designed testing protocol of change of direction speed (CODS) and reactive agility (RAG) in the clinical population. Research comprised 25 individuals older than 40 years of age who underwent knee surgery. Variables included age, gender, anthropometric characteristics, RAG, and CODS tests. Results displayed new tests as being reliable among patients after knee surgery. Also, tests were valid with regard to body mass and age (with better results in younger and lighter participants). Participants achieved similar results in CODS and RAG, with strong correlation between tests, which implies that CODS and RAG represent similar abilities in this population. Future studies should investigate the metric characteristics of here proposed tests in other subsamples.

Effects of Three Different Combined Training Interventions on Jump, Change of Direction, Power Performance, and Inter-Limb Asymmetry in Male Youth Soccer Players.

Background: This study compared the effects of performing different unilateral combined training interventions on diverse vertical and horizontal jumping performance parameters, change of direction, concentric and eccentric mean power, and their associated inter-limb asymmetries in young soccer players. Methods: Forty-seven young male soccer players (age: 15.5 ± 0.9 years) were distributed into three groups. Two groups performed the same training volume with both legs, beginning with the weaker leg (Stronger Volume Weaker leg group (SVW), n = 14) or with the stronger leg (Stronger Volume Stronger leg group, (SVS), n = 15). The third group executed double the volume with the weaker leg and also commenced with such leg (Double Volume Weaker leg group (DVW), n = 16) during a 10-week period. Pre- and post-intervention tests included a single-leg hop, single-leg lateral hop, triple hop, bilateral and unilateral countermovement jumps, a change of direction speed test, concentric and eccentric mean power during the lateral squat test, and their corresponding asymmetries. Results: Single-leg hop weaker leg, triple hop weaker leg, and bilateral countermovement jump improvements were achieved in the SVW (ES: 0.29 to 0.46) and DVW (ES: 0.55 to 0.73) groups. Between-groups analysis showed better results in single-leg hop in the SVW and DVW compared to group SVS. The DVW group achieved better improvements in countermovement jump in comparison to groups SVS and SVW. Conclusions: Groups that started with the weaker leg seemed to achieve a greater volume of significant changes than when starting with the stronger leg. Performing a double volume on the weaker limb does not guarantee further improved performance compared to other groups.

Change of Direction Speed Tests in Basketball Players: A Brief Review of Test Varieties and Recent Trends.

Change of direction speed (CODS) is essential for basketball performance, extensively assessed by various tests. This review aimed to summarize the CODS test varieties for basketball players on publications until 2019 and identify recent trends regarding what types of tests have gained attention in the 2010s. Electronic literature searches were conducted using three databases with relevant keywords. 104 studies were found eligible, conducting CODS tests 159 times in total with 48 test varieties. To facilitate distinctions between the tests, each test was categorized into one of three types based on the distinctive movement characteristics and changing angles as follows: Defensive (involving lateral shuffling), 180°-turn (exerting only 180°-turns), and Cutting (performing diagonal- or side-cut). We then counted the number of publications and adopted times reported per year for each test, and calculated the adoption rate for each categorized test type. The first CODS test performed in basketball players was the T-Test, reported in 1991, and this was the most commonly adopted test (44/159 times). The 2010s saw abrupt increases in the number of publications (1990s-2000s-2010s: 5-9-90) and test varieties (4-7-44). The adoption rates in the 2010s were similar among the three types (i.e., Defensive/180°-turn/Cutting: 37%/30%/33%), with the Cutting type gradually increasing over the last three decades (1990s-2000s-2010s: 0%-9%-33%). These results suggest that while CODS performances in basketball players are increasingly studied with various tests, recent studies give equal weight to all of the three categorized test types, with increasing adoption of the Cutting type, to assess specific CODS performances.

Associations between Inter-Limb Asymmetries in Jump and Change of Direction Speed Tests and Physical Performance in Adolescent Female Soccer Players.

The association between asymmetries in jump and change of direction (COD) with physical performance in several sports show inconclusive results. The purposes of this study were to: (1) measure inter-limb asymmetries in three distinct groups in adolescent female soccer players and, (2) to determine the association between inter-limb asymmetries and physical performance in different age groups. Fifty-four players were distributed in three age groups: U-18, U-16 and U-14. All of them performed a series of jumps, sprints and change of direction speed tests. Asymmetries were assessed as the percentage difference between limbs, with the equation: 100/Max value (right and left) * in value (right and left) * −1 + 100. Mean inter-limb asymmetries were 2.91%, 4.82% and 11.6% for 180° COD, single leg hop and single leg countermovement jump tests respectively, but higher percentages of asymmetries were observed in many players individually. U-18 and U-16 showed significant differences on 180° left COD compared to U-14. Effect size (ES): 0.80 and 0.74, respectively; U-18 presented differences on single left leg hop test compared to U-14, ES: −0.72; U-16 also showed differences on 40 m speed compared to U-14, ES 0.87 (All p < 0.05). Jumping and COD physical tests show asymmetries in adolescent female soccer players, but these asymmetries do not interfere with physical performance. The largest asymmetry was observed in the single leg countermovement jump, and no asymmetries between groups were found. Due to the high variability in the direction of asymmetries, it is recommended to consider players’ individual asymmetries for designing specific training programs.

RELIABILITY AND VALIDITY OF CHANGE-OF-DIRECTION SPEED TESTS FOR JUNIOR BASKETBALL PLAYERS

The main goal of this study was to determine the reliability and validity of change-of-direction speed (CODS) tests for junior basketball players and to test the differences between the positions of players on the team. On a sample of 66 junior basketball players (18.2±3.18 years), the CODS was tested using the following tests: the Lane Agility Test (LAT), Zigzag Agility Test (ZAT), Agility T-test and Modified Agility T-test. Body height and body mass were used as control variables. α-Cronbach's coefficient was calculated to determine the reliability and internal consistency of the measurements, as well as the average correlation between the trials of each test. The difference between groups of players was tested by MANCOVA. CODS tests showed good to high reliability (interclass correlations ranged from 0.83-0.93 with a variability of 4.4% to 6.4% for the entire sample). The first principal component was determined, which included 83% of the total variance of the analyzed variables. Very high coefficients of internal validity of all the applied tests (0.93-0.98) were obtained on the common subject of defined measurements. Significant differences were found between groups of players by position in favor of outside players (guards) on two tests LAT and ZAT (F=18.023; 8.559 and p≤0.005) with control of the influence of body height and body mass. All tests can be rated as reliable and valid for junior basketball players. LAT proved to be the most suitable for assessing the CODS in young basketball players, with the best discrimination of players by position on the team.

Does a Loaded Warm-Up Influence Jump Asymmetry and Badminton-Specific Change of Direction Performance?

Previously, it has been shown that loaded warm-up (LWU) can improve change-of-direction speed (CODS) in professional badminton players. However, the effect of asymmetry on CODS in badminton players and the influence of LWU on asymmetry has not been examined. A total of 21 amateur badminton players (age 29.5 [8.4] y, playing experience 8.4 [4.2] y) completed 2 trials. In the first, they performed a control warm-up. In the second, they performed the same warm-up but with 3 exercises loaded with a weight vest (LWU). Following both warm-ups, players completed single-leg countermovement jump and badminton-specific CODS tests. No significant differences between control warm-up and LWU were observed for CODS, single-leg countermovement jump, or single-leg countermovement jump asymmetry. However, small effect sizes suggested faster CODS (mean difference: -5%; d = -0.32) and lower asymmetries (mean difference: -3%; d = -0.39) following LWU. Five players (24%) experienced CODS improvements greater than the minimum detectable change while 2 (10%) responded negatively. Asymmetry was not correlated with CODS following control warm-up (ρ = .079; P = .733) but was negatively associated with CODS after LWU (ρ = -.491; P = .035). LWU may prove a strategy to trial on an individual basis, but generic recommendations should not be applied.

Relationship between Physical Factors and Change of Direction Speed in Team Sports

The relationship between the change of direction speed (CODS) and sprint speed, jump ability, and muscle strength is well recognized. However, the strength of this relationship may depend on how the test is designed and which parameters are analyzed. This scoping review aims to: (1) map the literature that addresses the relationships between the CODS and physical fitness and performance variables in players of team sports; (2) specify the limiting factors of CODS; and (3) identify gaps in existing literature and propose future research on this topic. Altogether, 22 research studies met the defined inclusion criteria. Most studies revealed significant correlations between CODS and sprint speed, muscle strength, and jump ability. This relationship was mainly demonstrated between CODS and linear sprint speed for 30 m (r = 0.60 to 0.74), 10 m (r = 0.39 to 0.65), maximal leg strength (r = −0.51 to −0.89), particularly explosive (r = −0.44 to −0.81), and reactive strength (r = −0.37 to −0.65). However, the strength of this relationship depends on the type of CODS test, its structure (total running distance, number of changes in direction), and parameters analyzed (height, power, velocity, and relative or absolute values). The recommendation for future research is to focus on choosing the test and its parameters to be close to the fitness demands of the particular sport.

How early should you brake during a 180° turn? A kinetic comparison of the antepenultimate, penultimate, and final foot contacts during a 505 change of direction speed test

ABSTRACT The aim of the study was to compare ground reaction force (GRF) characteristics between the antepenultimate foot contact (APFC), penultimate foot contact (PFC), and final foot contact (FFC), and to examine the relationships between APFC, PFC, and FFC GRF characteristics with 505 change of direction (COD) speed performance. Twenty university male soccer players performed three COD trials, whereby GRFs were collected over the aforementioned foot contacts. Greater peak braking forces in shorter ground contact times were demonstrated over the APFC compared to the PFC and FFC (p ≤ 0.011, d = 0.96–7.82), while APFC mean GRFs were greater than the PFC (p ≤ 0.001, d = 1.86–7.57). Faster 505 performance was associated with greater APFC peak and mean vertical, horizontal, and resultant braking GRFs (r2 = 21.6–54.5%), greater FFC mean HGRFs (r2 = 38.8%), more horizontally orientated peak resultant APFC and PFC GRFs (r2 = 22.8–55.4%), and greater APFC, PFC, and FFC mean horizontal to vertical GRF ratios (r2 = 32.0–61.9%). Overall, the APFC plays a more pivotal role in facilitating deceleration compared to the PFC for effective 505 performance. Practitioners should develop their athletes’ technical ability to express force horizontally across all foot contacts and coach braking strategies that emphasise greater magnitudes of posteriorly directed APFC GRFs to facilitate faster 505 performance.

Change-of-Direction Deficit vs. Deceleration Deficit: A Comparison of Limb Dominance and Inter-limb Asymmetry between Forwards and Backs in Elite Male Rugby Union Players

ABSTRACT The aims of the present study were to: 1) determine whether limb dominance and inter-limb asymmetry were the same across both change of direction (COD) and deceleration (DEC) deficits and, 2) determine the association between the COD and DEC-deficits and other physical performance tests in elite male rugby union players. Twenty five players performed a series of bilateral jumps, linear and COD speed tests at the end of the pre-season period. COD and DEC-deficits were calculated for both left and right sides, and inter-limb asymmetry thereafter. Kappa coefficients revealed moderate levels of agreement in limb dominance between COD and DEC-deficits (Kappa = 0.41 on left; 0.48 on right). For the direction of asymmetry, perfect levels of agreement (Kappa = 1) were evident between 505 time and COD-deficit, but only moderate levels of agreement (Kappa = 0.41) between other asymmetry measures. Pearson’s r correlations showed moderate to large relationships between jumps and linear (r = −0.42 to −0.68) and COD speed (r = −0.41 to −0.58), but not with the COD-deficit (r = 0.15 to −0.31), DEC-deficit (r = 0.01 to −0.32) or asymmetry (r = 0.16 to −0.29). When analysing by playing position, backs were significantly faster than forwards over 15-m (ES = −0.86) and across all jump tests (ES = 0.86–0.94), with the exception of the squat jump. This study is the first to provide a direct comparison of the COD and DEC-deficits and highlights that limb dominance and asymmetry cannot be guaranteed between tasks.