Linear Sprint Research Articles

Velocity and Power-Load Association of Bench Press Exercise in Wheelchair Basketball Players and Their Relationships With Field-Test Performance.

This study analyzes the relationship between mean propulsive velocity (MPV) of the bar and relative load (%1RM) in the bench press exercise, as well as determining the relationship of power variables (i.e. Mean Power (MP), Mean Propulsive Power (MPP) and Peak Power (PP)) in change of direction ability (CODA), linear sprint and RSA performance. Nine Spanish First Division wheelchair basketball (WB) players participated in the study. All participants performed an isoinertial bench press (BP) test in free execution mode, 505 change of direction ability test (505 CODA), linear sprint test (20 m), and Repeated Sprint Ability Test (RSA). A nearly perfect and inverse relationship was observed for the BP exercise between the %1RM and MPV (r = -.97; R2 = .945; P < 0.001). The maximum loads for MP, MPP and PP were obtained between 48.1 - 59.4% of the 1RM. However, no significant correlations were observed between strength and wheelchair performance. WB players with different functional impairments showed a nearly perfect and inverse relationship for the BP exercise between the %1RM and MPV, thus the MPV could be used to estimate the %1RM. This finding has important practical applications for velocity-based resistance training in which coaches would be able to prescribe and monitor training load. Conversely, the absence of association between BP performance and field tests might be due to other factors such as wheelchair-user interface, trunk muscular activity or propulsion technique apart from strength variables.

Caffeine Supplementation Has No Effect on Dribbling Speed in Elite Basketball Players.

To examine the effect of caffeine supplementation on dribbling speed in elite female and male basketball players. A double-blind, counterbalanced, randomized, crossover design was utilized. Elite basketball players (n = 21; female, n = 10; male, n = 11; age = 18.3 ± 3.3 yr) completed placebo (3 mg·kg-1 of body mass of dextrose) and caffeine (3 mg·kg-1 of body mass) trials 1 week apart during the in-season phase. During each trial, players completed 20-m linear sprints with and without dribbling a basketball. Performance times were recorded at 5-m, 10-m, and 20-m splits. Dribbling speed was measured using traditional (total performance time) and novel (Dribble Deficit) methods. Dribble Deficit isolates the added time taken to complete a task when dribbling compared to a non-dribbling version of the same task. Comparisons between placebo and caffeine conditions were conducted at group and individual levels. Non-significant (P > 0.05), trivial-small (effect size = 0.04-0.42) differences in dribbling speed were observed between conditions. The majority (20 out of 21) of players were classified as non-responders to caffeine, with 1 player identified as a negative responder using Dribble Deficit measures. Results indicate caffeine offers no ergogenic benefit to dribbling speed in elite basketball players. The negative response to caffeine in one player indicates caffeine supplementation may be detrimental to dribbling speed in specific cases and emphasizes the need for individualized analyses in nutrition-based sport science research.

Reliability of the Maximal Resisted Sprint Load Test and Relationships With Performance Measures and Anthropometric Profile in Female Field Sport Athletes.

Petrakos, G, Tynan, NC, Vallely-Farrell, AM, Kiely, C, Boudhar, A, and Egan, B. Reliability of the maximal resisted sprint load test and relationships with performance measures and anthropometric profile in female field sport athletes. J Strength Cond Res 33(6): 1704-1714, 2019-Resisted sled sprint (RSS) training is an effective modality for the improvement of linear sprint speed. Previous methods of RSS load prescription, e.g., an absolute load or as a percentage of body mass (%BM), do not account for interindividual differences in strength, power, or speed characteristics, although the "maximum resisted sled load" (MRSL) method of RSS load prescription may provide a solution. Maximum resisted sled load is defined as the final RSS load before an athlete can no longer accelerate between 2 phases (10-15 and 15-20 m) of a 20-m linear sprint. However, the MRSL test has not been analyzed for reliability. In addition, MRSL performance has not been compared with the outcome of other performance tests. The primary aim of this study was to investigate the reliability of the MRSL testing protocol in female field sport athletes. Participants (age, 20.8 ± 1.9 years; body mass, 64.3 ± 8.4 kg; height, 1.66 ± 0.65 m) tested for anthropometric measurements, strength and power performance testing, and twice for MRSL. Maximum resisted sled load values ranged from 20.7 to 58.9% BM. Maximum resisted sled load test-retest reliability intraclass correlation coefficient, confidence intervals, and coefficient of variations were 0.95, 0.85-0.98, and 7.6%, respectively. Maximum resisted sled load was"moderately" and "strongly" correlated with a number of anthropometric and performance tests (p ≤ 0.05), including percentage fat free mass, countermovement jump, loaded countermovement jump, rate of force development, horizontal jump, and horizontal bound performance. Maximum resisted sled load is a reliable measure for determining the RSS load at which an individual can no longer accelerate during a single RSS effort over 0-20 m. Maximum resisted sled load also accounts for interindividual variation in body composition, power, and speed characteristics of female field sport players.

Correlation between Sprint Tests and Agility 505 Test and Ktest in Elite Young Soccer Players

Agility, acceleration, change of direction (COD), deceleration, and sprinting are critical technical skills in soccer. The ability to sprint and quickly change direction are determinants of performance in a soccer game. Sprint performance relative to a new Agility K-test and 505 tests were examined. PURPOSE: To examine the relationship between the sprint and agility tests in elite young soccer players. METHODS: Elite Czech young male soccer players (n=29, age=19.5±0.4yrs) volunteered for this study. The KT consisted of the subjects running at maximum speed between cones positioned in a “K” pattern on a field with non-slip running surface. The subjects started and ended running at the intersection of the “K” pattern with two conditions: touching a photocell with the foot (KT_foot) or a contact switch placed on the top of each cone with the hand (KT_hand). The 505 COD test allowed subjects a “flying start” with a 10 m run-up before crossing the timing gates, a five-meter sprint, turn 180° either right or left and a final five-meter sprint. Linear sprinting was also tested with subjects sprinting 5 m (S5) and 10 m (S10) from a static position. The subjects performed two trials of each test, and the time of test execution was measured in seconds. Pearson correlation coefficient test was used to correlate two dependent variables, and independent t-test was used to test differences between KT_hand and KT_foot. P<.05. RESULTS: The correlation tests between dependent variables showed weak to moderate correlations. Specifically, 505_R vs S5=.45, p<.05; 505_R vs S10=.49, p<.01; 505_L vs S5=.11, NS; 505_L vs S10=.11, NS; KT_foot vs S5=.34, NS; KT_foot vs S10=.32, NS; KT_hand vs S5=.30, NS; KT_hand vs S10=.41, p<.05. The association between KT_foot and KT_hand=.18. NS. T-test showed the significance, t(56)=17.48, p<.01. CONCLUSSION: Specific “movement strategy” may exist in 505 COD tests due to asymmetries that may exist from the one-side dominant nature of the participants. However, due to multiple direction tested, KT-hand coordination “eye-hand” is faster and a more natural motor pattern than KT-foot. The speed variables exhibited significant heterogeneity. Speed and agility are not dependent; therefore, each component of speed must be considered independently when designing training programs for young soccer athletes.

Comparative Effects of Game Profile-Based Training and Small-Sided Games on Physical Performance of Elite Young Soccer Players.

Dello Iacono, A, Beato, M, and Unnithan, V. Comparative effects of game profile-based training and small-sided games on physical performance of elite young soccer players. J Strength Cond Res 35(10): 2810-2817, 2021-This study was designed to investigate and compare the effects of game profile-based training (GPBT) and small-sided game (SSG) training on physical performances of elite youth soccer players during the in-season period. Twenty young soccer players (18.6 ± 0.6) were randomly assigned to either GPBT or SSG protocols performed twice a week for 8 weeks. The GPBT consisted of 2 sets of 6-10 minutes of intermittent soccer-specific circuits. The SSG training consisted of 3-5 sets of 5 vs. 5 SSGs played on a 42 × 30-m pitch. Before and after the training program, the following physical performances were assessed: repeated sprint ability, change of direction (COD), linear sprinting on 10 m and 20 m, countermovement jump, and intermittent running (YYIRL1). Significant improvements were found in all the assessed variables after both training interventions (p < 0.05). The GPBT group improved more than the SSG group in the 10-m and 20-m sprint tests by 2.4% (g = 0.4; small effect) and 4% (g = 0.9; large effect), respectively. Conversely, the SSG group jumped 4% higher (g = 0.4; small effect) and resulted 6.7% quicker than the GPBT (g = 1.5; large effect) in completing the COD task. These results suggest both GPBT and SSGs to be effective for fitness development among elite young soccer players during the competitive season. More importantly, these 2 conditioning methodologies may be considered in terms of specificity for selectively improving or maintaining specific soccer fitness-related performances in the latter phase of the season.

Differences in Change of Direction Speed and Deficit Between Male and Female National Rugby Sevens Players.

Freitas, TT, Alcaraz, PE, Calleja-González, J, Arruda, AFS, Guerriero, A, Kobal, R, Reis, VP, Pereira, LA, and Loturco, I. Differences in change of direction speed and deficit between male and female national rugby sevens players. J Strength Cond Res 35(11): 3170-3176, 2021-The aims of this study were to assess the change of direction (COD) deficit in different tasks and to investigate the differences in COD ability and COD deficit between male and female rugby sevens players. Thirty-six elite rugby players from the Brazilian National senior sevens teams (18 males and 18 females) completed the following physical assessments: squat and countermovement jumps; drop jump from a 45-cm height; horizontal single and triple jumps; 40-m linear sprint; Pro-agility, L-drill, and Zig-zag COD tests; and 1 repetition maximum test in the squat exercise. The differences between male and female performances were determined using magnitude-based inferences, an independent t test, and effect sizes (ES). Pearson's product-moment correlations were performed to determine the relationships among the different COD velocities and COD deficits. Men demonstrated likely to almost certainly significantly higher performances than women in all speed-power assessments and COD tasks (ES ranging from 0.61 to 2.09; p < 0.05), with the exception of the Zig-zag drill (ES = 0.24; p > 0.05). Furthermore, males displayed significantly greater COD deficits in all tests and higher sprint momentum (ES ranging from 0.78 to 2.95; p < 0.05). Large significant relationships among COD velocities (r ranging from 0.71 to 0.88; p < 0.05) and almost perfect significant correlations among all COD deficits (r ranging from 0.90 to 0.95; p < 0.05) were obtained in both sexes. The present results indicate that male rugby players are less efficient at changing direction, relative to their maximum sprint velocity. In addition, the correlations between the different COD deficits and COD speeds suggest that elite rugby players demonstrate similar ability to change direction, independently of the angle of directional change. From a practical perspective, this implies that a more comprehensive training strategy including eccentric exercises, acceleration-deceleration drills, and directional change technique is warranted to improve the COD ability (and reduce the COD deficit) of faster and more powerful rugby sevens players.

Maximum acceleration performance of professional soccer players in linear sprints: Is there a direct connection with change-of-direction ability?

The purpose of this study was to examine the selective influences of the maximum acceleration capability on change of direction (COD) speed, COD deficit, linear sprint speed, sprint momentum, and loaded and unloaded vertical jump performances in forty-nine male professional soccer players (24.3 ± 4.2 years; 75.4 ± 5.4 kg; 177.9 ± 6.4 cm). Soccer players performed the assessments in the following order: 1) squat and countermovement jumps; 2) 20-m sprinting speed test; 3) Zigzag COD ability test; and 4) bar-power outputs in the jump squat exercise. Athletes were divided, using a median split analysis, into two different groups according to their maximum acceleration rates from zero to 5-m (e.g., higher and lower ACC 0-5-m). Magnitude-based inference was used to compare the differences in the physical test results between “higher” and “lower” acceleration groups. A selective influence of the maximum acceleration ability on speed-power tests was observed, as the higher acceleration group demonstrated likely to almost certain higher performances than the lower acceleration group in all measurements (effect sizes varying from 0.66 [for sprint momentum in 20-m] to 2.39 [for sprint velocity in 5-m]). Conversely, the higher acceleration group demonstrated a higher COD deficit when compared to the lower acceleration group (ES = 0.55). This indicates compromised efficiency to perform COD maneuvers in this group of players. In summary, it was observed that soccer players with higher maximum acceleration rates are equally able to jump higher, sprint faster (over short distances), and achieve higher COD velocities than their slower counterparts. However, they appear to be less efficient at changing direction, which may be related to their reduced ability to deal with greater entry and exit velocities, or counterbalance the associated mechanical consequences (i.e., greater inertia) of being faster and more powerful.

Effects of an Eccentric Hamstrings Training on Components of Physical Performance in Young Female Handball Players.

This study examined the effects of an 8-week Nordic hamstring exercise (NHE) training on components of physical performance in young female handball players. Participants were allocated to an experimental group (EG; n = 10; age: 15.9 [0.2]y) and a control group (CG; n = 9; age: 15.9 [0.3]y). The EG performed NHE (2-3sessions/wk) in replacement of some handball-specific drills, whereas the CG followed regular handball training. Pretraining and posttraining tests were carried out for the assessment of sprint speed (5m, 10m, and 20m), jump performance (countermovement jump [CMJ] height), change-of-direction (t test), and repeated-sprint ability (RSA total time [RSAtotal], RSA best time [RSAbest], and RSA fatigue index [RSAFI]). Data were analyzed using magnitude-based inferences. Within-group analyses for the EG showed moderate performance improvements for 5, 10, and 20m (effect size [ES] = 0.68-0.82), t test (ES = 0.74), and CMJ (ES = 0.85). Trivial to small improvements were observed for RSA (ES = -0.06 to 0.35). For the CG, within-group outcomes showed performance decrements with moderate (t test [ES = 0.71]), small (5m [ES = 0.46] and RSAbest [ES = 0.20]), and trivial magnitude (10m [ES = 0.10], 20m [ES = 0.16], and RSAtotal [ES = 0.00]). Furthermore, trivial to small performance improvements were found for CMJ (ES = 0.10) and RSAFI (ES = 0.5). Between-group analyses revealed small to large effects in favor of EG for 5m (ES = 1.07), 10m (ES = 0.66), 20m (ES = 0.53), t test (ES = 1.38), and RSA (ES = 0.68-0.78). A trivial between-group difference was demonstrated for CMJ (ES = -0.01). The NHE training intervention, in replacement of some handball-specific drills, was more effective than regular handball training in improving physical performance (ie,linear sprint time, jumping, change-of-direction, and RSA) in young female handball players.

Differential effects of low vs. high inertial loads during an eccentric-overload training intervention in rugby union players: a preliminary study.

Eccentric overload training (EOT) has been proposed as an effective stimulus to optimize dynamic athletic performance. Nevertheless, the appropriate intensity during EOT remains unknown. The purpose of this study was to evaluate the influence of the inertial load used during an EOT program on performance adaptations in rugby union players. Fifteen rugby players were divided into a low (0.025 kg·m2; G 0.025) or a high (0.075 kg·m2; G 0.075) inertial load for training. Both groups trained using the flywheel half squat exercise twice a week during the seven-week EOT. Athletic performance was evaluated by testing the half squat maximum repetition (1RM), countermovement jump (CMJ), 40 m linear sprint, the modified agility T-Test, and power output in the flywheel squat exercise. Data were analysed using magnitude-based inferences. Both groups improved their 1RM and CMJ to a similar extent. Nevertheless, the G 0.025 showed likely trivial changes in linear sprint (ES=-0.02), and possibly positive effects on the agility T-Test (ES=0.16), while the G 0.075 showed possibly negative effects on 40 m linear sprint (ES=-0.23) and likely trivial effects on the T-Test (ES=0.07). Due to the similar gains in 1RM and CMJ, and the superior maintenance in linear sprint, the use of low inertial loads during EOT may be a better option when looking for athletic performance optimization.

Comparison of Physical Fitness and Anthropometrical Profiles Among Brazilian Female Soccer National Teams From U15 to Senior Categories.

Ramos, GP, Nakamura, FY, Penna, EM, Mendes, TT, Mahseredjian, F, Lima, AM, Garcia, ES, Prado, LS, and Coimbra, CC. Comparison of physical fitness and anthropometrical profiles among Brazilian female soccer national teams from U15 to senior categories. J Strength Cond Res 35(8): 2302-2308, 2021-This study aimed to compare anthropometric and physical fitness of Brazilian female national team soccer players from the U15 to senior categories, and to compare the physical performance between selected and nonselected players. Subjects included 231 athletes (U15, n = 46, U17, n = 49, U20, n = 98, and Senior, n = 38). Body mass, height, sum of skinfolds, squat jump (SJ), countermovement jump (CMJ), 20-m linear sprint, and Yo-Yo IR1 were assessed. The U15 players were shorter than all other groups (p < 0.01) and lighter than U20 players (p < 0.01). Regarding physical tests, Senior athletes presented higher SJ compared with U20, and both showed higher CMJ and SJ compared with the U15 and U17 (p < 0.05). Senior athletes were also faster than players of all other categories in 20-m sprint (p < 0.01) and covered the greatest distance in the Yo-Yo IR1 (p < 0.05). U20 were better in the Yo-Yo IR1 than the younger groups (p < 0.05). When comparing selected and nonselected players, no differences were identified in anthropometric measures (p > 0.05). However, selected players from U17, U20, and Senior teams showed better performance in Yo-Yo IR1 than nonselected ones (p < 0.05). Finally, selected senior athletes also presented higher CMJ and SJ than nonselected players (p < 0.05). These results suggest that, although there is a tendency for maintenance in anthropometric measures from the age of 15 years, there are substantial improvements in speed, lower-body power, and aerobic capacity from U20 age group. In addition, it seems that intermittent aerobic fitness contributes to the selection of players to international tournaments in national teams.

Dissociation between changes in sprinting performance and Nordic hamstring strength in professional male football players.

The aim of the present study was to evaluate the consequence of implementing a Nordic Hamstring exercise (NHE) protocol during the first 15 to 17 weeks of the season to assess the effect on sprinting and NHE strength (NHEs) in professional football players. The study examined 50 healthy male professional football players (age 18.8±0.8yr; height 176.8±6.9cm; weight 71.3±5.7kg) belonging to 3 of the reserve squads of three Spanish La-Liga clubs divided in 2 intervention teams [Nordic-Group1 (NG-1) and Nordic-Group2 (NG-2, extensive experience in NHE)] and 1 team as a control-group (CG). NHEs and linear sprint (T5, T10, T20-m) were evaluated at the beginning of the season and at the end of an intervention period of conditioning and football training, supplemented with a NHE protocol (24 sessions for NG-1 and 22 sessions for NG-2) or without using the NHE at all (CG). Sprint times were substantially improved in all groups (ES from -2.24±0.75 to -0.60±0.37). NHEs was enhanced absolute and relative to body-mass only in NG-1 after the training period (ES from 0.84±0.32 to 0.74±0.26), while in the NG-2 there were only improvements in average NHEs relative to body-mass (ES = 0.39±0.36). The improvements in T20-m were substantially greater in NG-2 vs. NG-1, and there were no differences in sprint performance changes between NG-1 and CG. Changes in sprinting performance and NHEs were unrelated. NHEs was largely correlated with the body-mass of the players. Results indicate that the improvements in sprint are not dependent on the NHEs changes, with no relationships between NHEs and sprint performance, and between sprint changes and changes in NHEs.

Initial Maximum Push-Rim Propulsion and Sprint Performance in Elite Wheelchair Rugby Players.

García-Fresneda, A, Carmona, G, Padullés, X, Nuell, S, Padullés, JM, Cadefau, JA, and Iturricastillo, A. Initial maximum push-rim propulsion and sprint performance in elite wheelchair rugby players. J Strength Cond Res 33(3): 857-865, 2019-Wheelchair rugby (WR) is an increasingly popular Paralympic sport; however, the evidence base supporting the validity and reliability of field tests to assess the physical condition of WR players is in its infancy. Therefore, here, we aimed to evaluate the intrasession reliability of the initial maximum push-rim propulsion (IMPRP) test and the sprint test, and to determine the relationships between IMPRP mechanical outputs and sprint performance variables. We studied 16 Spanish WR players (aged 33 ± 9 years). The maximum single wheelchair push from a stationary position and the sprint performance (i.e., times for 3, 5, and 12 m, and the maximum velocity) of elite WR players were measured in this study. The intraclass correlation coefficient, coefficient of variation, and standard error of measurement for IMPRP variables were >0.85, <10.6%, and <16.76, respectively; the corresponding values for a linear sprint were >0.97, <3.50%, and <0.15. In relation to IMPRP mechanical outputs (i.e., acceleration, maximum acceleration, force, maximum force, power, and maximum power) and sprint performance (i.e., times for 3, 5, and 12 m, and the maximum velocity), significant and large associations were observed in the WR players (r ± confidence limit = -0.78 ± 0.17 to -0.90 ± 0.11; 0/0/100, most likely; R = 0.613-0.812; p < 0.001). These tests provide simple and reliable methods for obtaining accurate mechanical pushing capacities and sprint performances of WR competitors (the 61.4-80.1% variance in sprint performance was explained by the IMPRP variables). These relationships indicate a need to implement specific strength exercises in WR players with the aim of improving the IMPRP and therefore improving sprint capacity.

Change-of-direction, speed and jump performance in soccer players: a comparison across different age-categories

ABSTRACT This study examined the age-specific development of vertical jump height, straight and change-of-direction (COD) speed, and COD deficit in one-hundred and eighty-two elite soccer players from different age-categories (U15, U17, U20, and Senior). All participants were players of two distinct clubs and were undertaking different training routines, as planned by their technical staff members. For this purpose, the soccer players performed: (1) squat and countermovement jumps; (2) a maximal 20-m linear sprint speed test, and (3) the Zigzag COD test. The magnitude-based inference approach and standardized differences were used to compare the age-groups. Sprint speed at longer distances (20-m) increased progressively across the age-ranges. In contrast, speed and acceleration performances at shorter distances (5-m) were better in U15 than in the other age-categories. The COD speed did not change throughout the younger categories but presented a meaningful decrease in the Senior category. Surprisingly, despite the progressive increase in volume and intensity of neuromuscular training from younger to older categories, the COD deficit presented a gradual increase across the age-groups. It is possible that simple modulation of the strength-power training program during the maturation process is not sufficient to produce faster adult players with enhanced ability to change direction. Therefore, coaches are strongly encouraged to implement specific COD training practices to tolerate braking at increasing running speeds and appropriate volume and intensity of soccer specific training throughout the players’ specialization process.

Can Positioning Systems Replace Timing Gates for Measuring Sprint Time in Ice Hockey?

This study explores whether positioning systems are a viable alternative to timing gates when it comes to measuring sprint times in ice hockey. We compared the results of a single-beam timing gate (Brower Timing) with the results of the Iceberg optical positioning system (Optical) and two radio-based positioning systems provided by InMotio (Radio 1) and Kinexon (Radio 2). The testing protocol consisted of two 40 m linear sprints, where we measured sprint times for a 11 m subsection (Linear Sprint 11), and a shuttle run (Shuttle Total), including five 14 m sprints. The exercises were performed by six top-level U19 field players in regular ice hockey equipment on ice. We quantified the difference between measured sprint times e.g., by Mean Absolute Error (MAE) (s) and Intra Class Correlation (ICC). The usefulness of positioning systems was evaluated by using a Coefficient of Usefulness (CU), which was defined as the quotient of the Smallest Worthwhile Change (SWC) divided by the Typical Error (both in s). Results showed that radio-based systems had a higher accuracy compared to the optical system. This concerned Linear Sprint 11 (MAEOptical = 0.16, MAERadio1 = 0.01, MAERadio2 = 0.01, ICCOptical = 0.38, ICCRadio1 = 0.98, ICCRadio2 = 0.99) as well as Shuttle Total (MAEOptical = 0.07, MAERadio1 = 0.02, MAERadio2 = 0.02, ICCOptical = 0.99; ICCRadio1 = 1.0, ICCRadio2 = 1.0). In Shuttle Total, all systems were able to measure a SWC of 0.10 s with a probability of >99% in a single trial (CUOptical = 4.6, CURadio1 = 6.5, CURadio2 = 5.1). In Linear Sprint 11 an SWC of 0.01 s might have been masked or erroneously detected where there were none due to measurement noise (CUOptical = 0.6, CURadio1 = 1.0, CURadio2 = 1.0). Similar results were found for the turning subsection of the shuttle run (CUOptical = 0.6, CURadio1 = 0.5, CURadio2 = 0.5). All systems were able to detect an SWC higher than 0.04 s with a probability of at least 75%. We conclude that the tested positioning systems may in fact offer a workable alternative to timing gates for measuring sprints times in ice hockey over long distances like shuttle runs. Limitations occur when testing changes/differences in performance over very short distances like an 11 m sprint, or when intermediate times are taken immediately after considerable changes of direction or speed.

Dribble Deficit Enables Measurement of Dribbling Speed Independent of Sprinting Speed in Collegiate, Male, Basketball Players.

Ramirez-Campillo, R, Gentil, P, Moran, J, Dalbo, VJ, and Scanlan, AT. Dribble Deficit enables measurement of dribbling speed independent of sprinting speed in collegiate, male, basketball players. J Strength Cond Res 35(7): 2040-2045, 2021-The aim of this study was to determine the relationships between sprinting and dribbling speed in basketball during linear and change-of-direction (COD) sprints using total dribbling time and Dribble Deficit. Collegiate, male, basketball players (n = 10; 21.0 ± 1.6 years) performed linear and COD sprints with and without dribbling a ball. Linear dribbling sprints were measured for the dominant and nondominant hands, whereas COD dribbling sprints involved bilateral use of hands. Dribble Deficit was determined as the difference between total time (second) during each dribbling trial and the equivalent nondribbling trial for linear and COD sprints. Simple linear regression analyses were performed during linear and COD sprints to determine the relationship (R) and shared variance (R2) between (a) sprinting times and total dribbling times and (b) sprinting times and Dribble Deficit. Large to very large, significant relationships were evident between linear sprinting and dribbling time for dominant (R = 0.86; R2 = 0.74, p = 0.001) and nondominant hands (R = 0.80; R2 = 0.65, p = 0.005). Trivial relationships were apparent between linear sprinting time and Dribble Deficit with dominant (R = 0.10; R2 = 0.01, p = 0.778) and nondominant hands (R = 0.03; R2 = 0.00, p = 0.940). A very large relationship was evident between COD sprinting and dribbling time (R = 0.91; R2 = 0.82, p < 0.001), whereas a trivial relationship was observed between COD sprinting time and COD Dribble Deficit (R = -0.23; R2 = 0.05, p = 0.530). Dribble Deficit eliminates the strong influence of sprinting speed on outcome measures typically seen when using tests predicated on total dribbling time. Consequently, Dribble Deficit may be of added use in basketball test batteries to measure dribbling speed across linear and multidirectional movement paths.

Effects of Plyometric Training on Physical Performance of Young Male Soccer Players: Potential Effects of Different Drop Jump Heights.

To compare the effects of plyometric drop jump (DJ) training against those induced by regular soccer training and assess the transference effect coefficient (TEC) of DJs ("trained exercises") performed from 20- (DJ20) and 40-cm (DJ40) height boxes with respect to different physical qualities (jumping, linear and change of direction speed, kicking, endurance, and maximal strength) in youth male soccer players. Participants were randomly divided into a control group (n = 20; age: 13.5 [1.9]y) and a DJ training group (n = 19; age: 13.2 [1.8]y), and trained for 7 weeks. A 2-way analysis of variance for repeated measures with the within-subject factor time (preintervention and postintervention) and between-subject factor group (intervention vs control) was performed. To calculate the TECs between the trained exercises (DJ20 and DJ40) and the physical tests, the ratio between the "result gains" (effect size [ES]) in the analyzed physical qualities and the result gains in the trained exercises were calculated. The TECs were only calculated for variables presenting an ES ≥ 0.2. Significant improvements (ES = 0.21-0.46; P < .05) were observed in the DJ training group, except in linear sprint performance. The control group improved only the maximal strength (ES = 0.28; P < .05). Significant differences were observed in all variables (ES = 0.20-0.55; P < .05) in favor of the DJ training group, except for maximal strength (group × time interaction). A plyometric training scheme based on DJs was able to significantly improve the physical performance of youth male soccer players. Overall, greater TECs were observed for DJ40 (0.58-1.28) than DJ20 (0.55-1.21).

Running technique is more effective than soccer-specific training for improving the sprint and agility performances with ball possession of prepubescent soccer players.

Soccer-specific training is easily associable to players’ sprint abilities demonstrated during a match. However, no clear evidence has been provided to show whether this approach is more effective than training focused on running techniques for sprints in prepubescent soccer players. Thus, the present study aimed at comparing the effects of these two training approaches on prepubescent soccer players’ sprint performances. Ninety-five players (10±2 years) competing in local (Piedmont, Italy) Under-9 (N=21), -10 (N=24), -11 (N=25) and -13 (N=25) championships were recruited for the study. Sixty-three and 32 players were included in the running training group (RTG) and soccer-specific group (SSG), respectively. Before (PRE) and after (POST) the training period (2 weekly sessions for 12 weeks), sprint abilities were evaluated by means of four 20-m sprint tests: linear sprint (20-mL), linear sprint with ball possession (20-mLB), sprint with change of direction (20-mCoD), sprint with change of direction and with ball possession (20-mCoDB). A linear mixed model was applied to evaluate differences (P≤0.05) between the RTG and SSG in the four tests and categories, comparing PRE and POST performances. A main effect emerged for the interaction between groups, sessions (p=0.014; Between PRE ES range=0.03, 0.85; Within PRE-POST ES range=-0.45, 0.09), highlighting a POST improvement of RTG for the 20-mLB (Δ=-7.9%; ES=0.85) and 20-mCoDB (Δ=-5.9%; ES=0.33). In contrast, no improvements emerged for the SSG. The present findings indicate that the training approach of the RTG is more able to improve prepubescent soccer players’ sprint performances than that of the SSG, with the emphasis on ball possession executions, which are particularly game-related.

Programirana i neprogramirana agilnost u diagnostici sportaša

The aim of the study is to examine the differences between four pre-planned and non-planned agility tests. The movement structure of the tests combined frontal, universal, semi-circular, and lateral agility components. The sample of participants comprised 45 male athletes and 31 female athletes. The time-based parameters for pre-planned and non-planned agility tests were determined using the FitLight Trainer, a wireless training system which is comprised of seven LEDpowered lights and controlled via an Android application. The results obtained were then statistically processed using the SPSS software package. Basic descriptive parameters were calculated for all the testing protocols. The differences between the pre-planned and non-planned test versions were evidenced by an independent T-test. A correlation analysis was performed to analyse the relationships between pre-planned and non-planned agility performances in the selected tests, as well as to determine the correlation between the agility performance and the space of linear sprint speed and reactive strength. The results of the study showed statistically significant differences in selected tests of pre-planned (non-reactive) and non-planned (reactive) agility between both sub-samples. Significant differences were also observed in the reactive and nonreactive agility tests for men as well as women. The difference between male and female athletes was the highest in the non-planned frontal agility test (FRA), followed by the pre-planned frontal agility test (FRA), and pre-planned semicircular agility test (SCA), whereas the global agility test (GLA) showed the lowest difference. In the sub-sample of male athletes, the difference between the known and unknown movement routines was highest in the global agility test (22.3%), while the lowest gap was reported in the relationship between the reactive and non-reactive lateral agility tests (13.5%). The differences between the pre-planned and non-planned agility tests in females were also statistically significant.

Change of Direction Deficit in National Team Rugby Union Players: Is There an Influence of Playing Position?

The aim of this study was to investigate the change of direction (COD) ability and deficits of elite rugby union players, discriminating between position (backs and forwards), and between “faster and slower players”, in multiple COD tasks. Twenty-four male rugby union players from the Brazilian senior National team completed the following assessments: Squat and countermovement jumps; drop jump; standing long jump, horizontal triple jumps; 40-m linear sprint; Pro-agility, L-Drill, and Zig-zag COD tests; and squat 1-repetition maximum. The differences between backs and forwards and between faster and slower performers were examined using magnitude-based inferences. Backs were faster (in both linear and COD speed tests) and jumped higher than forwards. Moreover, they generated an inferior sprint momentum. No differences were found in COD deficit between playing positions. However, when dividing the sample by median split, faster players outperformed their slower counterparts in all power–speed variables and presented higher COD deficits. These results suggest that separating rugby players by playing position might not discriminate players with different COD skills and that the median split analysis is more sensitive to identifying these differences. Furthermore, the present data indicate that faster rugby players are less efficient at changing direction and tolerating higher approach velocities in COD maneuvers.

Reliability and sensitivity of jumping, linear sprinting and change of direction ability tests in adolescent female football players

ABSTRACTPurpose: The aim of this study was to assess the reliability, sensitivity and performance changes across the season of jumping, linear sprinting and change of direction ability (CODA) tests in adolescent female football players.Materials and methods: A total of 60 female football players (U-16 and U-18) performed bilateral and unilateral countermovement jump tests, a single leg hop test, a 40-m linear speed test, and two CODA tests on two occasions separated by 5–7 days to assess test-retest reliability. Furthermore, test sensitivity was also calculated. Finally, 52 players performed each test three times throughout the season to analyse those performance changes.Results: Reliability scores showed a priori acceptable values in U-16 (ICC = 0.76–0.94; CV = 1.0–4.8%) and U-18 (ICC = 0.75–0.99; CV = 1.0–3.6%) in all tests. All tests were sensitive to detect large changes at both short- and mid-term with the exception of the V-cut test (only at short-tem) in both groups. Seasonal changes were mainly produced between baseline and Test 3 in linear sprinting and jumping measurements in U-16 and U-18, respectively.Conclusions: Jumping, linear sprinting and CODA tests are reliable and can detect moderate to large performance changes and they could be used to monitor their performance in U-16 and U-18 female football players.