20-m Sprint Time Research Articles

Variations in Physical and Competitive Performance of Highly Trained Sprinters Across an Annual Training Season.

Loturco, I, Fernandes, V, Bishop, C, Mercer, VP, Siqueira, F, Nakaya, K, Pereira, LA, and Haugen, T. Variations in physical and competitive performance of highly trained sprinters across an annual training season. J Strength Cond Res 37(5): 1104-1110, 2023-We assessed the changes in sprint, jump, and power parameters across the annual training cycle and tested the longitudinal correlations among these variables in top-level sprinters. Thirteen sprinters training with 4 different Olympic sprint coaches were sequentially assessed over 14 months, from January 2019 to March 2020, within 4 consecutive training camps. Performance tests were conducted as follows: standing long jump, squat and countermovement jumps, 10-m and 60-m sprint time, and maximum power output in the half-squat, jump-squat, and hip-thrust exercises. The competitive results of the sprinters throughout the study period were also recorded and analyzed. A repeated measures analysis of variance was used to compare the physical measurements between different testing sessions. A Pearson product-moment correlation was applied to examine the longitudinal relationships between changes in speed-related and power-related parameters. Percentage change was computed and compared with coefficient of variation values to determine whether changes in performance metrics were higher than the test variance, thus providing an indication of whether true changes occurred on an individual basis. Overall, sprinters did not exhibit significant changes in sprint speed, jumping ability, and power output. In addition, variations in competitive times (i.e., 100 m races) followed a similar pattern, within an average range of ±1.36%, for both male and female sprinters. As expected, top-level sprinters presented only small variations in physical and competitive performance over time. Nevertheless, the use of an individual statistical technique (i.e., true changes calculation) revealed that these nonsignificant increases or decreases may represent meaningful changes in their competitive potential.

Effects of High-Intensity Position-Specific Drills on Physical and Technical Skill Performance in Elite Youth Soccer Players.

Cuong Le, C, Ma'ayah, F, Nosaka, K, Hiscock, D, and Latella, C. Effects of high-intensity position-specific drills on physical and technical skill performance in elite youth soccer players. J Strength Cond Res 37(5): e332-e340, 2023-Soccer physical preparation has been extensively researched with previous emphasis on high-intensity interval running and small-sided games. However, neither approach considers positional differences. The purpose of this study was to investigate the feasibility and short-term effects of a novel position-specific conditioning training (PSCT) paradigm on physical and technical abilities of young soccer players. Fifteen male Vietnamese professional youth soccer players (16.1 ± 0.4 years, 171.7 ± 4.8 cm, 63.9 ± 3.8 kg) undertook a 3-week control period followed by a 3-week intervention with PSCT drills performed twice per week. Position-specific conditioning training comprised purposely designed drills for attackers, defenders, and wingers, respectively. The intensity and duration were the same for all drills (4 × 4 minutes at ∼90% heart rate maximum [HRmax], separated by a 4-minute recovery at 70% HRmax) but differed in the technical and tactical actions performed. Outcome measures included Yo-Yo intermittent recovery test level 1, repeated sprint ability, 10-m and 30-m sprint time, and the Loughborough Soccer Passing Test for technical skills in a fatigued and nonfatigued state. Position-specific conditioning training drills induced a desirable intensity for effective conditioning purpose (89.0 ± 2.1% HRmax) with low interplayer variability (coefficient of variation = 2.4%). Yo-Yo intermittent recovery test level 1 performance improved ( p < 0.05) after the control (Δ178.7 ± 203.3 m) and intervention (Δ176.0 ± 225.7 m) periods without a difference between. These results confirmed the feasibility of PSCT as a novel high-intensity training approach for soccer players. Improvements in aerobic capacity were noted, despite no effect on other physical and technical measures. PSCT may be suitable for individual training, return-to-play stages of rehabilitation, during off-season, or in academy settings when time is not a constraint.

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.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/edu_01/0587/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

The influence of short sprint performance, acceleration, and deceleration mechanical properties on change of direction ability in soccer players-A cross-sectional study.

The study investigated the relationship between short sprint performance and mechanical parameters obtained during the acceleration and deceleration tasks with the change of direction (COD) performance in female and male soccer players. The acceleration and deceleration ability were compared in the "High/Fast" versus "Low/Slow" COD performance group based on a median split analysis in each sex group. One hundred three French soccer players were assessed for the sprinting Force-Velocity (F-V) profile (i.e., theoretical maximal force [F0], velocity [V0], power [Pmax]), 10m performance, linear deceleration test (maximal braking force [HBFmax], braking power [BPmax], deceleration [Decmax]), and COD performance using 505-test. The 10m performance was strongly associated with 505-test performance (ES = [0.64 to 0.71]), whereas the sprinting F-V profiles parameters were weakly to moderately correlated with 505- performance (ES = [-0.47 to -0.38]). The BPmax was also moderately associated with 505-test performance (ES: range = [-0.55 to -0.46]). In addition, the High/Fast female COD group presented higher F0, Pmax, HBFmax, and BPmax than the Low/Slow group, whereas the male groups presented very few mechanical differences. Multiple regression analysis shows that the COD performance of male players was determined by 10m performance and maximum deceleration power. In contrast, no statistically significant model could be found to determine the change of direction performance in female players. In conclusion, the current finding indicated that the only variable strongly associated with COD performance was the linear 10m sprint time. In the same way, the mechanical parameters obtained from acceleration and deceleration seemed to play a non-neglectable role in this population.

Repeated Sprint Protocols With Standardized Versus Self-Selected Recovery Periods in Elite Youth Soccer Players: Can They Pace Themselves? A Replication Study

Replicating the studies of Gibson etal and Brownstein etal to assess performance, and physiological, and perceived variables during a repeated sprint protocol (RSP) with standardized versus self-selected recovery in youth soccer players. Nineteen male soccer players (age 13.1 [1.3]y) completed 2 separate RSPs. RSP1: 10 × 30-m sprints with 30-second recovery and RSP2: 10 × 30-m sprints interspersed with self-selected recovery periods. Mean time of both 10 × 30-m RSPs and self-selected recovery periods of RSP2 were assessed. Heart rate, blood lactate concentration, and rates of perceived exertion were measured following RSPs. RSP2 revealed longer recovery periods (RSP1: 30.0 [0.0]s; RSP2: 39.0 [7.7]s; P < .001; effect size d = 1.648) with shorter repeated sprint time (mean 30-m sprint time: RSP1: 4.965 [0.256]s; RSP2: 4.865 [0.227]s; P = .014; d = 0.414). Blood lactate concentration (P = .002-.005; d = 0.730-0.958), heart rate (P < .001; d = 1.353), and rates of perceived exertion (RSP1: 14.9 [1.9]; RSP2: 12.9 [2.1]; P = .016; d = 1.046) were higher following RSP1. In contrast to the original studies, the present replication study demonstrated that self-selected recovery periods during a RSP leads to better repeated sprint performance compared with standardized recovery periods in youth soccer players. The better repeated sprint performance with individual recovery durations in RSP2 was achieved with less physiological and perceived effort.

Does Dominant Somatotype Differentiate Performance of Jumping and Sprinting Variables in Young Healthy Adults?

The relationship between an athlete’s somatotype three-numeral rating and his or her athletic performance is well known. However, a direct effect of the different dominant somatotype on jumping and sprinting variables has not yet been reported. The aim of this study was to investigate the effects of dominant somatotype on sport-specific explosive variables. One hundred and twelve physically active young adults (mean ± standard deviation age: 21.82 ± 3.18 years) were somatotype-rated using the Heath–Carter method. Participants were classified as balanced ectomorph, balanced mesomorph, central, mesomorph-endomorph, and mesomorphic ectomorph. Vertical jump and linear sprint tests were performed to measure peak lower body performance and sprint variables (time, speed, and momentum), respectively. The analysis revealed that balanced mesomorph had significantly higher vertical jump (effect size (ES) = 1.10, p = 0.005) and power to body mass (ES = 1.04, p = 0.023) than mesomorph-endomorph. In addition, balanced mesomorph showed significantly superior performance in 30-m sprint time and velocity than central and mesomorph-endomorph (ES range = 0.93–1, p < 0.05). Finally, balanced ectomorph (ES = 1.12, p = 0.009) and mesomorphic ectomorph (ES = 1.10, p = 0.017) were lower in sprint momentum compared to balanced mesomorphs. In conclusion, this study has shown the importance of the interaction between subtypes and athletic performance. The knowledge gained may be important in identifying those who tend to perform well in sports with explosive power and in prescribing training programs.

Effect of electromyostimulation and plyometrics training on sports-specific parameters in badminton players

Badminton is one of the world's most popular racquet sports, demanding motor skills such as agility and vertical jump mainly for striking a shuttlecock. This study compared the effects of four weeks of plyometric training and electromyostimulation of knee extensor and ankle plantar flexor muscles on agility, 30-m sprint, lower limb explosive power and jumping ability amongst badminton players. State-level badminton players (n ​= ​90) were randomly allocated into three groups: plyometric (PG), electromyostimulation (EG) and control group (CG), each with 30 players. Randomized-to-Groups Pretest-Posttest Design with two experimental (plyometric and electromyostimulation) groups and a control group was used. The plyometric training was carried out two times/week while the EMS training was four times/week for four weeks. The control group did not receive any intervention. All three groups continued their general badminton training throughout the study. Players were assessed for agility, a 30-m sprint, a standing broad jump and a vertical jump height before and after four weeks. A significant improvement (p ​= ​0.01) in 30-m sprint time was observed (3.83%) in PG as compared to controls. Jumping ability was significantly improved in both the PG and EG in comparison to the controls (4.45%, p ​= ​0.003 for PG and 3.95%, p ​= ​0.048 for EG). No significant improvement was found in agility and lower limb explosive power in either of the PG or EG groups in comparison to the controls. Plyometric training showed significant improvement in sprint time and jumping ability, whereas electromyostimulation training showed significant improvement only in jumping ability.

BUILDING A PROFILE OF SPECIFIC FITNESS INDICES FOR MALE TEENAGE CHINESE SPRINTERS

ABSTRACT Objectives: This study aimed to construct a profile of specific fitness indices for male teenage sprinters on the Chinese National Team to provide sprinting fitness assessments for teenage training. Material and Methods: 229 male teenage sprinters at the same level were recruited to participate in this test for the indices. The t- and Kruskal-Wallis tests were conducted for the first selection of fitness indices. In the second selection, principal components analysis was applied to select common factors with greater characteristic values. The fitness indices chosen were height, leg length, measurement B (ankle circumference/heel length×100%) and measurement A (thigh circumference/leg length×100%), hemoglobin, 60m sprint time, 100m sprint time, countermovement jump (CMJ), maximum countermovement jump velocity, CMJ flight time, CMJ maximum force, and CMJ force. Results: Thirteen indices were chosen for the specific fitness of male teenage Chinese male sprinters with 3 general categories and 9 subcategories. The weight of each fitness index was confirmed and used to construct a standard fitness assessment scale. Conclusion: Anthropometric indices indicate the athlete’s innate limits in the structure of the sprinting motion. Physiological indices indicate the athlete’s potential to expend energy and recover in a short time. Motor indices indicate the athlete’s maximum sprinting ability, lower limb reaction strength, power, and maximum strength. Level of evidence II, Diagnostic studies - Investigation of a diagnostic test.

Fundamental Movement Skills and Physical Fitness Are Key Correlates of Tactical Soccer Skill in Grassroots Soccer Players Aged 8–14 Years

One hundred and twenty-one children (58 boys and 63 girls) aged 8–14 years (mean ± SD = 12 ± 1 years) who were regularly engaged in grassroots soccer participated in this study. Participants undertook assessments of fundamental movement skill (FMS) using the Test of Gross Motor Development-3, perceived ability using the Perceived Physical Ability Scale for Children, physical fitness via 15-m sprint time, standing long jump distance, and technical skill using the university of Ghent dribbling test. The Procedural Tactical Knowledge Test was employed as a measure of tactical skill from which metrics for positioning and movement and recognizing spaces were derived. Maturation was determined from anthropometric measures. Analysis of covariance examined gender differences in tactical skills accounting for FMS, fitness, perceived ability, technical skill, maturation, and age. Results indicated no significant differences in tactical skills between boys and girls (p &gt; .05). For recognizing spaces, 56% of the variance was explained with FMS (p = .001), physical fitness (p = .02), and technical skill (p = .02) contributing to the model. For positioning and movement, a significant model explained 55% of the variance in this element of tactical behavior with FMS (p = .002) and technical skill (p = .02) significantly contributing to the model.

Effect of 6 weeks of short intermittent running training versus small-sided games on heart rate variability, aerobic and anaerobic performance in Indian elite soccer players

Background: Soccer is characterized by long periods of low to moderate intensity activity interspersed with periods of high-intensity actions, such as single and repeated sprints. Therefore, a well-prepared soccer player must be able to endure long periods of low- to moderate intensity activity and sustain periods of explosive match effort intensification. Objective: To evaluate the effects of 6-weeks short interval running training and Small Sided Games on Heart Rate Variability measurements, aerobic capacity and performance in well trained Indian elite soccer players. Methods: A pretest – posttest experimental design was used in our study. 90 elite male soccer players was assigned into three groups by computer generated block randomization. Group I- Short Interval running Training (N-30), Group II- Small sided game Training (N-30) and Group III- Generic Training (control group, N-30). Autonomic control by HRV, vertical jump height, agility, 10m-30m sprint performance and VO2max by multistage fitness test was analysed. Result: Pre- intervention and post- intervention results was analysed and compared. The difference in agility, vertical jump height, 10m sprint time and VO2max was more in the SIRT group as compared the SSG and Generic (control) group. This difference was statistically significant (p&lt;0.001).

A 7-min halftime jog mitigated the reduction in sprint performance for the initial 15-min of the second half in a simulated football match.

This study compared the effects of a 7-min shuttle jog during halftime to a control condition (seated rest) on subsequent athletic performance and lower-leg temperature in the second half. Eighteen male football players (22 years, 179 cm, 70 kg, 10 years of athletic career) randomly performed a 20-m shuttle jog (at an intensity of 70% of heart rate maximum) and a seated rest (sitting on a bench) during halftime in two separate sessions. A 5-min football simulation protocol consisting of football-specific activities (jumping, sprinting, kicking, passing, and dribbling at various intensities and distances) was repeated nine times to mimic the first and second half of a football match. Athletic performance (maximal vertical jump height, 20-m sprint time, and the Arrowhead agility test time) recorded during a 15-min period were averaged to represent each time point (first half: T1 to T3; second half: T4 to T6). Lower-leg skin and muscle (using the insulation disk technique) temperature was recorded before and after the first and second half. There was no condition effect over time in maximal vertical jump: F5,187 = 0.53, p = 0.75, Arrowhead agility test time: F5,187 = 1.25, p = 0.29, and lower-leg temperature (skin: F3,119 = 1.40, p = 0.25; muscle: F3,119 = 1.08, p = 0.36). The 20-m sprint time between conditions during the initial 15-min of the second half was different (condition × time: F5,187 = 2.42, p = 0.04) that subjects who performed the shuttle jog ran 0.09 sec faster (3.08 sec, p = 0.002, ES = 0.68), as compared with those who did the seated rest (3.17 sec). The results of our study confirmed that a decremental effect of the static rest on sprinting performance during the initial period of the second halftime can be attenuated by a halftime warm-up.

Immediate Effects of Spinal Manipulative Therapy on the Performance of Elite Brazilian Soccer Players: A Pilot Randomized Controlled Trial With an Internally Validated Sham Treatment

ObjectiveThe purpose of this study was to assess the feasibility of the procedures’ routine, the recruiting rate, the presence of any significant detrimental impact on the players’ training routine, and the sham efficacy in achieving blinding. MethodsA parallel randomized controlled clinical trial was performed with 20 elite soccer players who were randomly assigned to 1 of 2 groups: spinal manipulative therapy (SMT) and sham SMT. All players were from the same team, were injury free, and were naive to SMT. Measured outcome tests (30-m sprint run with a 10-m split and change of direction [COD] test) were performed at the same time by all participants immediately before and after interventions. Photocell devices were used for data acquisition. ResultsTwenty participants were analyzed (10 in each group). There were no changes to the sprint (10 m and 30 m) and COD test results immediately after either of the interventions. All participants in both groups (SMT and sham SMT) answered “yes” to a question after the intervention asking if they were treated by SMT. No adverse effects or training routine impairment were reported. ConclusionThis pilot study protocol showed it was an appropriate design for a confirmatory clinical trial. The study had minimal effect on the team training routine, and the recruitment rate was excellent. The proposed sham SMT strategy was successful in blinding the players. In this sample, SMT did not have any immediate effect on the performance of these elite soccer players, as measured by 10- and 30-m sprint times and COD sprint times.

Comparing the Effects of Long-Term vs. Periodic Inclusion of Isometric Strength Training on Strength and Dynamic Performances.

Lum, D, Joseph, R, Ong, KY, Tang, JM, and Suchomel, TJ. Comparing the effects of long-term vs. periodic inclusion of isometric strength training on strength and dynamic performances. J Strength Cond Res 37(2): 305-314, 2023-This study compared the effects of including isometric strength training (IST) for consecutive 24 weeks (CIST) against a periodic inclusion (PIST) of this mode of training on strength and dynamic performances. Twenty-four floorball athletes (age: 23 ± 2.7 years, stature: 1.74 ± 2.08 m, and body mass: 72.7 ± 14.4 kg) were randomly assigned to the control (CON), CIST, or PIST group. Athletes completed 20-m sprint, countermovement jump (CMJ), and isometric midthigh pull (IMTP) during pre-test and were tested on weeks 6, 12, 18, and 24. All groups performed a similar strength training program twice per week. However, 2 sets of squats were replaced with isometric squat in CIST for all 24 weeks but only on weeks 1-6 and 13-18 for PIST. A significant main effect for time was observed for 5-, 10-, and 20-m sprint time, CMJ height, peak force, peak power, time to take-off, modified reactive strength index, IMTP peak force, relative peak force, and force at 200 milliseconds ( p = <0.001-0.037). Isometric strength training for 24 consecutive weeks resulted in greater improvement in 5-m sprint time than CON at week 24 ( p = 0.024, g = 1.17). Both CIST and PIST resulted in greater improvements in 10-m sprint time than CON at various time points ( p = 0.007-0.038 and 0.038, g = 1.07-1.44 and 1.18, respectively). Isometric strength training for 24 consecutive weeks and PIST resulted in greater improvements in 20-m sprint time than CON at week 6 ( p = 0.007 and 0.025, g = 1.65 and 1.40, respectively). The results showed that the inclusion of IST resulted in greater improvements in sprint performance than CON but no significant difference in all measured variables with PIST.

Speed Improves With Eccentric Hamstring Training in Athletes of Different Maturity Status.

To investigate the effects of an eccentric hamstring strength training program (EHT) on sprint performance (10-, 20-, and 30-m sprint times) and change of direction speed (4 × 5-m shuttle run and T-Half test) in male European handball athletes at 2 maturity statuses (prepeak and postpeak height velocity [PHV]). Forty-five participants (12.68 [1.58]y) were divided into pre-PHV and post-PHV and randomly allocated to a control or intervention group, which performed a guided 2day per week 6-week EHT of 5 exercises. A mixed-model (within- and between-factor) analysis of variance was conducted. A significant effect (P < .05) of the interaction time × maturity × training was observed in the T-Half, 10, and 30m tests. Both intervention groups significantly improved in all the tests, except in the 20m sprint and the post-PHV in the 10m sprint. Improvements ranged between 0.93% and 5.74% (effect size: 0.07-0.79). Both control groups yielded no improvements in almost all the tests. The improvements of both groups undergoing the intervention (pre-PHV and post-PHV) were not significantly different (only a tendency in the 10m sprint). An EHT program combined with European-handball training improve change of direction and sprint performance in pre-PHV and post-PHV male players. Professionals training European handball and similar team-sport athletes should consider including EHT regardless of athlete's maturity.

Correlation of pitching velocity with anthropometric measurements for adult male baseball pitchers in tryout settings.

Several studies have investigated factors influencing baseball pitching velocity. However, some measurements require expensive equipment, and some tests need familiarity to perform well. In this study, we adopted field tests executed using affordable equipment in a tryout event for a professional baseball team in Taiwan, 2019. We use half day to test 64 players, and the result of measurement are used to develop a model for predicting pitching velocity of amateur adult pitchers (age: 23.9 ± 2.8 years; height: 180.3 ± 5.9 cm; weight: 81.4 ± 10.9 kg). The measurements and tests in tryout settings should be easy to implement, take short time, do not need high skill levels, and correlate to the pitching velocity. The outcome measures included maximum external shoulder rotation, maximum internal shoulder rotation, countermovement jump (CMJ) height, 20-kg loaded CMJ height, 30-m sprint time, height, age, and weight tests. Multiple regression indicated a moderate correlation between these tests and pitching velocity (adjusted R2 = 0.230, p = 0.0003). Among the measures, the ratio of loaded CMJ to CMJ, ratio of first 10-m sprint time to 30-m sprint time, and height were significant contributors to pitching velocity. Overall, these measures explained 23% of the variance in the predicted pitching velocity. These field tests can be adopted in tryout events to predict a prospect's potential and to identify underestimated players. Coaches can obtain an expectation of a pitcher's performance by comparing his pitching velocity with the predicted value derived from the statistical model presented herein, and the room of growth by comparing his current strength to average strength growth after being drafted and trained with professional coaches.

Effects of two low-volume high-intensity interval training protocols in professional soccer: sprint interval training versus small-sided games.

The programming of training protocols within a high-intensity interval training (HIIT) framework with appropriate analysis of total training load could deliver optimal training adaptations. This study aims to compare the efficiency of two low-volume HIIT protocols integrated with the regular training regime in professional soccer players. Twenty-five participants aged 18.4-29.7 years were randomly assigned to one of two interventions involving straight-line sprint interval training (SIT, N.=13) or small-sided games (SSG, N.=12). Periodization was divided into two 3-week phases concluded by a 7-day taper. SIT first involved two-session·week-1 of one set of 10·45-s sprints (at maximal intensity) and then three-session·week-1 of two sets of 10·30-s sprints with a 0.75:1 and 1:1 recovery interval (slow running and stretching exercises), respectively. SSG in the first phase involved 5·3-min games of 4 vs. 4 and in the second phase 4·4-min games of 2 vs. 2 with 3-min recovery (practice drills at 60-70% HR<inf>max</inf>). Training load was controlled via session-RPE and HR-based methods. Pre- and postintervention testing included: countermovement jump height, 5-m and 30-m sprints performance, anaerobic power by the 10-s Wingate Anaerobic Test, maximal oxygen uptake (V̇O<inf>2max</inf>) and blood lactate concentration (BLa-) determined by incremental exhaustive running test. Two-way ANOVA showed group×time interaction effects for the 30-m sprint time (F<inf>(1,23)</inf>=3.023; P=0.049; η2 P=0.116), BLa- (F<inf>(1,23)</inf>=5.250; P=0.031; η2 P=0.185), and V̇O<inf>2max</inf> (F<inf>(1,23)=</inf>4.648, P=0.044; η2 P=0.157). SIT elicited greater enhancements in anaerobic performance (30-m sprint time and BLa-), while SSG induced larger improvements in V̇O<inf>2max</inf>. Comparable effects of SIT and SSG protocols were noted, however the aerobic capacity benefits provided by SSG warrant this HIIT protocol as a highly recommended training modality in the professional soccer.

Effects of contrast strength training with elastic band program on sprint, jump, strength, balance and repeated change of direction in young female handball players

Maximal strength, power and his derivates (sprint, change of direction repeatedly and jump) are considered as major determinants of success in elite handball players. Contrast strength training with elastic band (CSTEB) program is form of resistance training, and may play an important method of training to improve this quality. This study examined the effects of 10-week contrast strength training with elastic band (CSTEB) program on physical performance in young female handball players. Thirty participants (age: 15.7 ± 0.3 years; body mass: 63.7 ± 3.7 kg; body height: 166.8 ± 3.8 cm; body fat: 26.9 ± 3.4; and Maturity-offset: 2.9 ± 0.3 years) were randomly assigned between experimental group (EG; n = 15) and control group (CG; n = 15). Two-way analyses of variance (group × time) were assessed for handgrip; back extensor; medicine ball throw; 30-m sprint times; Modified Illinois change-of-direction (Illinois-MT); four jump tests [(squat jump (SJ), countermovement jump (CMJ), countermovement jump with arms (CMJA) and five jump test (5JT)]; static (stork) and dynamic (Y balance) balance tests; and repeated sprint T-test (RSTT). The EG enhanced all strength performance [handgrip right, handgrip left, back extensor strength and medicine ball throw (p &lt; 0.001)] compared to CG. The EG enhanced all sprint performance. The EG also improved performance in the Illinois-MT. All jump performance improved significantly [SJ (p = 0.007), CMJ (p = 0.001) and CMJA (p = 0.001)] except 5JT in the EG. Of the same, 3 of 4 repeated sprint T-test scores [RSTT-Best-Time, RSTT-Mean-Time and RSTT-Total-Time] increased significantly in the EG relative to the CG. Conversely, there were no significant changes in balance performance between groups. It is concluded that 10-weeks of CSTEB improved physical performance (strength, sprint, change of direction, jump, and repeated change of direction) measures in young female handball players.

Strength Training in Professional Soccer: Effects on Short-sprint and Jump Performance.

Several studies have confirmed the efficacy of strength training to maximize soccer player performance during competition. The aim of this meta-analysis was to determine the effects of different strength training protocols on short-sprint and vertical jump performance of professional soccer players from the first division of their countries. The following inclusion criteria were employed for the analysis: (a) randomized studies; (b) high validity and reliability instruments; (c) studies published in a high-quality peer-reviewed journal; (d) studies involving professional soccer players from the first division; (e) studies with descriptions of strength training programs; and (f) studies where countermovement jump and 10-m sprint time were measured pre and post training. Overall, the different strength-oriented training schemes produced similar performance improvements, which seem not to depend on the training strategy. Strength training appears to have a lower effect when applied during in-season than when applied in pre-season periods in first division soccer players. In this meta-analysis it is not possible to confirm that strength training in isolation is capable of improving the short-sprint and jump performance of elite soccer players. The congested fixture schedule and, thus, the limited time to perform complementary (non-specific) training sessions, may contribute to these reduced effects.

The Reliability and Validation of the Aquatic Movement Protocol as an Instrument for Assessing Aquatic Motor Competence in Primary Aged Children

There is a dearth of research in aquatic motor competency, a key requirement for primary physical education in order to become physically literate. This study proposes a new assessment protocol for aquatic motor competence and sets out to examine the validity of the Aquatic Movement Protocol (AMP) in children between 7 and 9 years of age. Testing of Gross Motor Development—second edition was implemented to assess general motor competence, including a composite of 10-m running sprint time and standing long jump distance. Aquatic motor competence was assessed by the AMP. Univariate analyses of covariance were used to examine whether assessment of general motor competence differed as opposed to aquatic motor competence. Process and product measures of dryland motor competence were analyzed using male and female subjects measuring three aquatic motor competences (low, medium, and high). Cronbach’s alpha and exploratory factor analyses were implemented to show both construct and concurrent validity of the AMP. Children classified as high for aquatic motor competence had significantly higher general motor competence (p = .001). Those who achieved a higher composite score for faster sprint speeds and longer jump distances had significantly higher aquatic motor competence (p = .001). Cronbach’s alpha of .908, showed internal consistency of the AMP. Results extracted one factor from analysis with an eigenvalue = 6.2; %variance = 62.1, with loadings higher than 0.5. This data suggests that the items on the AMP measure a single construct that we would call “Aquatic Motor Competence.” This study demonstrates that the AMP is a valid measure of aquatic motor competence in primary aged children.

Knee Extensor Morphology and Sprint Performance in Preadolescent Sprinters

ABSTRACT Purpose: We previously reported that the cross-sectional area of the quadriceps femoris is correlated with the sprint performance of preadolescent sprinters. This finding suggests a close relationship between knee extensor torque-enhancing morphology and sprint performance in this young population. To further clarify this issue, in this study, we examined the relationships of the quadriceps femoris muscle volume (MV) and knee extensor moment arm (MA) with sprint performance in preadolescent sprinters. Methods: The quadriceps femoris MV and knee extensor MA in 15 sprint-trained preadolescent boys were measured using magnetic resonance imaging. Sprint performance was evaluated using a personal best 100-m sprint time and the higher 50-m sprint velocity of two 50-m sprint tests. Results: The quadriceps femoris MV and knee extensor MA were significantly correlated with personal best 100-m sprint time (r = −0.810 and −0.752, P ≤ 0.001 for both) and 50-m sprint velocity (r = 0.814 and 0.702, P < .01 for both). Furthermore, the relative quadriceps femoris MV normalized to body mass was significantly correlated with both the personal best 100-m sprint time (r = −0.620, P = .014) and 50-m sprint velocity (r = 0.686, P = .005). In contrast, no significant correlations were observed between the relative knee extensor MA normalized to body height and both sprint performance parameters. Conclusions: These findings suggest that the quadriceps femoris size, rather than the knee extensor MA dimension, is a more important morphological factor for achieving superior sprint performance in preadolescent sprinters.