Training and testing physical capacities for elite soccer players

Elite soccer players spend a substantial amount of time trying to improve physical capacities, including aerobic endurance and strength and the strength derivatives of speed and power. The average oxygen uptake for international soccer teams ranges from 55 to 68 ml.kg-1.min-1 and the half-squat maximal strength from 120 to 180 kg. These values are similar to those found in other team sports. Recently, it has been shown that the heart's stroke volume is the element in the oxygen chain that mainly limits aerobic endurance for athletes. These findings have given rise to more intensive training interventions to secure high stroke volumes, which, in turn, have proved positive in changing both maximal oxygen consumption and soccer performance in terms of distance covered, contacts with the ball and number of sprints in a game. The training employed has consisted of 4x4-min "intervals" running uphill at 90-95% of maximal heart rate interspersed with 3 min jogging at 70% of maximal heart rate to facilitate removal of lactate. Research has revealed that a soccer-specific training routine with the ball might be as effective as plain running. Strength training to produce neural adaptations has been effective in changing not only strength in terms of "one-repetition maximum", but also sprinting velocity and jumping height, in elite soccer players without any change in body mass. The same training has also improved running economy and thus aerobic endurance performance. The training regimen used for a European Champions League team was 4x4 repetitions of half-squats with the emphasis on maximal mobilization of force in the concentric action.     

Stress hormonal analysis in elite soccer players during a season

PurposeThe purpose of this study was to evaluate the changes in some hormonal parameters (cortisol, testosterone, ratio of testosterone/cortisol (T/C)) in professional soccer players during a season.MethodsFifteen professional players from a soccer club of the first division of the Greek soccer league participated. All sport medical examinations were conducted four times: before the re-building period, post re-building period, mid-season, and after finishing the competition phase.ResultsFor testosterone, significant differences were observed between the end season and post re-building period (11.6%; p < 0.05) and mid-season (12.1%; p < 0.05). The cortisol concentration increased at mid-season by approximately 23%, and this change differed significantly from all other measurements for this hormone. The T/C ratio increased at the post re-building period and decreased at the middle of the season.ConclusionThese hormones and their ratios could be used as stress and recovery state indicators. Coaches can use these parameters in combination with other indicators to optimize workloads, and to avoid overreaching and overtraining.     

Academic performance and self-regulatory skills in elite youth soccer players

Abstract

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12–16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.     

Functional hamstrings: quadriceps ratios in elite women's soccer players

Abstract

We compared starters and non-starters for various isokinetic strength variables in elite women’s soccer players. A convenience sample of 10 starters (mean ± s; age = 20 ± 2 years; height = 170 ± 4 cm; body mass = 65 ± 5 kg) and 7 non-starters (age = 20 ± 1 years; height = 164 ± 3 cm; body mass = 63 ± 4 kg) performed maximal voluntary muscle actions of the leg extensors (concentric) and flexors (eccentric) on an isokinetic dynamometer in order to measure concentric peak torque for the leg extensors, eccentric peak torque for the leg flexors, and the functional hamstrings:quadriceps (H:Q) ratio at 1.047 rad · s^-1 and 4.189 rad · s^-1 concentric peak torque for the leg extensors was not different between starters and non-starters. However, it was greater at 1.047 rad · s^-1 than at 4.189 rad · s^-1 in both groups. Eccentric peak torque for the leg flexors was greater for the starters versus non-starters at 4.189 rad · s^-1. Eccentric strength of the leg flexors at fast movement velocities may be used as an effective physiological profile and may discriminate between playing status in elite women’s soccer players.     

Academic performance and self-regulatory skills in elite youth soccer players

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12-16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.     

Biomechanical mechanisms of jumping performance in youth elite female soccer players

ABSTRACT

We aimed to determine key biomechanical parameters explaining age-related jumping performance differences in youth elite female soccer players. Multiple biomechanical parameters from countermovement (CMJ) squat (SJ) and drop (DJ) jump testing of elite female soccer players (n = 60) within the same national training centre were analysed across ages 9-11y, 12-14y and 15-19y. Effects of age group and jump type on jump height were found, with the older jumping higher than the younger groups in all jumps (P < 0.05). For DJ, higher reactive strength index was found for older, compared to each younger group (P < 0.001). For CMJ and SJ, peak power was the most decisive characteristic, with significant differences between each group for absolute peak power (P < 0.0001) and body-weight-normalised peak power in CMJ (57 ± 7W/kg, 50 ± 7W/kg, 44.7 ± 5.5W/kg; P < 0.05) and between the older and each younger group in SJ (56.7 ± 7.1W/kg, 48.9 ± 7.1W/kg, 44.6 ± 6W/kg; P < 0.01). Age-related differences in jumping performance in youth elite female soccer players appear to be due to power production during standing jumps and by the ability to jump with shorter ground contact times during reactive jumps.     

Tensiomyography parameters and jumping and sprinting performance in Brazilian elite soccer players

Tensiomyography has been suggested as an indirect marker of muscle stiffness, which is associated with strength/power performance. Therefore, it is reasonable to suggest that tensiomyography parameters could be associated with power-related motor tasks. The purpose of this study was to investigate the association between tensiomyography parameters (from rectus and biceps femoris) and jumping and sprinting abilities in elite soccer players. In addition, we used tensiomyography parameters to compare the lateral symmetry between dominant and non-dominant legs. Twenty elite soccer players (age: 23.3 ± 4.8 years; height: 183.5 ± 6.6 cm; weight: 77.8 ± 7.5 kg) volunteered to participate in the study. Significant moderate negative correlations between biceps femoris displacement and contact time (r = –0.5, p = 0.03), rectus femoris displacement and contact time (r = –0.51, p = 0.02), and a significant moderate correlation between biceps femoris displacement and reactive strength index (r = 0.5, p = 0.03) were found. There were no correlations between tensiomyography parameters and power-related motor tasks. In addition, no differences in tensiomyography parameters between dominant and non-dominant legs were found. Our data suggest that tensiomyography parameters are not associated with power-related motor tasks performance in elite soccer players.     

Self-regulation and performance level of elite and non-elite youth soccer players

Abstract

In learning and development, self-regulation can be described as the extent to which individuals are metacognitively, motivationally, and behaviourally proactive participants in their learning process (Zimmerman, 1989 Zimmerman, B. J. 1989. A social cognitive view of self-regulated academic learning. Journal of Educational Psychology, 81: 329–339. [Crossref], [Web of Science ®] , [Google Scholar], 2006 Zimmerman, B. J. 2006. “Development and adaptation of expertise: The role of self-regulatory processes and beliefs”. In The Cambridge handbook of expertise and expert performance, Edited by: Ericsson, K. A., Charness, N., Feltovich, P. J. and Hoffman, R. R. 705–722. New York: Cambridge University Press. [Crossref] , [Google Scholar]). We examined the relationship between self-regulation and performance level in elite (n = 159) and non-elite (n = 285) youth soccer players aged 11–17 years (mean 14.5 years, s = 1.4). The players completed a questionnaire that assessed planning, self-monitoring, evaluation, reflection, effort, and self-efficacy. A logistic regression analysis was performed (controlling for age) to determine which self-regulatory aspects were associated with players' performance level (elite vs. non-elite). High scores on reflection and effort were associated with a higher level of performance. Findings suggest that elite players may be more aware of their strong and weak points as well as better able to translate this awareness into action. In addition, elite players appear to be more willing to invest effort into practice and competition. It is suggested that these better developed self-regulatory skills may translate into a more effective learning environment and ultimately result in an increased capacity for performance in elite players relative to their non-elite peers.     

Power training in elite young soccer players: Effects of using loads above or below the optimum power zone

ABSTRACT

This study aimed to examine the effects of two jump squat (JS) training programs involving different loading ranges in under-20 soccer players during a preseason period. Twenty-three elite young soccer players performed sprint speed (at 5-, 10-, and 20-m), change-of-direction (COD) speed, JS peak-power (PP), and countermovement jump (CMJ) tests pre and post four weeks of training. Athletes were pair-matched in two groups according to their optimum power loads (OPL) as follows: lower than OPL (LOPL; athletes who trained at a load 20% lower than the OPL) and higher than OPL (HOPL; athletes who trained at a load 20% higher than the OPL). Magnitude-based inferences were used to compare pre- and post-training measures. Meaningful increases in the PP JS were observed for both groups. Likely and possible improvements were observed in the 5- and 10-m sprint velocity in the LOPL group. Meanwhile, possible and likely improvements were observed in the CMJ, 5- and 10-m sprint velocity, and COD speed in the HOPL group. Overall, both training schemes induced positive changes in athletic performance. Soccer coaches and sport scientists can implement the JS OPL-based training schemes presented here, either separately or combined, to improve the physical performance of youth soccer players.     

Pre-game hydration status, sweat loss, and fluid intake in elite Brazilian young male soccer players during competition

In this study, we assessed the pre-game hydration status and fluid balance of elite young soccer players competing in a match played in the heat (temperature 31.0 ± 2.0 ° C, relative humidity 48.0 ± 5.0%) for an official Brazilian soccer competition. Fluid intake was measured during the match, as were urine specific gravity and body mass before and after the game to estimate hydration status. Data were obtained from 15 male players (age 17.0 ± 0.6 years, height 1.78 ± 0.06 m, mass 65.3 ± 3.8 kg); however, data are only analysed for 10 players who completed the full game. The mean (± s) sweat loss of players amounted to 2.24 ± 0.63 L, and mean fluid intake was 1.12 ± 0.39 L. Pre-game urine specific gravity was 1.021 ± 0.004, ranging from 1.010 to 1.025. There was no significant correlation between sweat loss and fluid intake (r = 0.504, P = 0.137) or between urine specific gravity and fluid intake (r = -0.276, P = 0.440). We conclude that young, native tropical soccer players started the match hypohydrated and replaced about 50% of the sweat lost. Thus, effective strategies to improve fluid replacement are needed for players competing in the heat.     

Sleep quantity and quality in elite youth soccer players: A pilot study

This study examined the effect of early evening high-intensity training on the sleep of elite male youth soccer players (n = 12) using wrist actigraphy. High-intensity training (TRAIN) nights were compared with a home environment (HOME) condition, created by averaging sleep variables on the night before and after TRAIN nights. Additionally, after TRAIN athletes alternately used cold water immersion (TRAIN+CWI) or none, to assess whether cold water immersion (CWI) had any impact on sleep quality and quantity. Ratings of perceived exertion, fatigue and recovery were recorded after training. Actigraphy sleep measures were bedtime, wake time, sleep duration, sleep onset latency, sleep efficiency and wake after sleep onset. Self-rated scores of sleepiness at bedtime and wake, plus overall sleep quality were also recorded. Only fatigue ratings were higher in TRAIN compared to TRAIN+CWI at bedtime, there were no other differences in training data. Both TRAIN and TRAIN+CWI conditions had significant later (07:45 ± 1:09 h p < 0.01 and 07:34 ± 1:20 h p = 0.01) wake times than HOME (06:44 ± 0:41 h). The TRAIN condition had a significantly higher (7 ± 2; p < 0.01) rating of sleepiness at bedtime compared to HOME (6 ± 1), but no further differences were found in any of the sleep (actigraphy and self-reported) measures. Across all conditions, time spent asleep was ～7:30 (±0:52) h:min and sleep efficiency was ～89% (±6.1). In conclusion, early evening high-intensity training had no impact on subsequent sleep quality and quantity, nor was there any effect on sleep after performing CWI post-training.     

Comparing the magnitude and direction of asymmetry during the squat,countermovement and drop jump tests in elite youth female soccer players

ABSTRACT

The aims of the present study were to provide an in-depth comparison of inter-limb asymmetry and determine how consistently asymmetry favours the same limb during different vertical jump tests. Eighteen elite female under-17 soccer players conducted unilateral squat jumps (SJ), countermovement jumps (CMJ) and drop jumps (DJ) on a portable force platform, with jump height, peak force, concentric impulse and peak power as common metrics across tests. For the magnitude of asymmetry, concentric impulse was significantly greater during the SJ test compared to CMJ (p = 0.019) and DJ (p = 0.003). No other significant differences in magnitude were present. For the direction of asymmetry, Kappa coefficients revealed fair to substantial levels of agreement between the SJ and CMJ (Kappa = 0.35 to 0.61) tests, but only slight to fair levels of agreement between the SJ and DJ (Kappa = ?0.26 to 0.18) and CMJ and DJ (Kappa = ?0.13 to 0.26) tests. These results highlight that the mean asymmetry value may be a poor indicator of true variability of between-limb differences in healthy athletes. The direction of asymmetry may provide a useful monitoring tool for practitioners in healthy athletes, when no obvious between-limb deficit exists.     

山东省优秀青年女子排球运动员接发球技术分析

针对山东青年女子排球队员接发球质量不高的问题,应用 APAS 录像解析软件对6名主力接发球队员进行三维录像定量分析。将接发球动作分为准备阶段,移动阶段和击球阶段,根据测试结果分别找出每名队员在各阶段存在的问题,并针对不同的问题提出相应的改进建议。     

Age and maturity related differences in motor coordination among male elite youth soccer players

This study investigated differences in generic and soccer specific motor coordination, as well as speed and agility depending on age and maturity in elite youth soccer players (U10-U15, N = 619). Measurements included body height, body weight and sitting height to estimate age at peak height velocity (APHV); three Körperkoordinationstest für Kinder subtests (i.e. jumping sideways (JS), moving sideways (MS), balancing backwards (BB)) to assess generic motor coordination; the UGent dribbling test for soccer specific motor coordination; a 5m/30m sprint and T-test for speed and agility, respectively. Age specific z-scores of the predicted APHV identified players as earlier, on time or later maturing. (M)ANOVA analyses showed significant age by maturity interaction effects for the speed and agility test cluster, revealing maturity related differences in U14 and U15 players. Next to an overall higher performance with age for all test clusters (η² 0.080–0.468), earlier maturing players outperformed their later maturing peers in 5m/30m sprinting. The opposite was seen for JS and BB. So, players’ maturity status should be taken into account to adequately value performance in talent identification. Also, the focus on characteristics that appear to be minimally biased by an earlier maturational timing (i.e. motor coordination) should be increased.     

Match-derived relative pitch area changes the physical and team tactical performance of elite soccer players in small-sided soccer games

Small-sided games (SSGs) are used in training sessions to prepare for full-sized matches. For the same number of players, smaller pitch sizes result in decreased physical performance and shorter interpersonal distances. A relative pitch area derived from the full-sized match results in larger pitch sizes and this may increase the fit between SSGs and full-sized matches. This study aimed to investigate SSGs with a traditional small pitch and a match-derived relative pitch area in youth elite soccer players. Four age categories (under-13, under-15, under-17 and under-19) played 4 vs. 4 plus goalkeepers on a small (40x30m, 120m² relative pitch area) and large pitch (68x47m, 320m² relative pitch area). The number of games per age category ranged 15–30. Positional data (LPM-system) were collected to determine physical (total distance covered, high intensity distance and number of sprints) and team tactical (inter-team distance, LPW-ratio, surface area, stretch indices, goalkeeper-defender distance) performance measures and tactical variability. On a large pitch, physical performance significantly increased, inter-team and intra-team distances were significantly larger and tactical variability of intra-team distance measures significantly increased. The match-derived relative pitch area is an important training manipulation and leads to changes in physical and tactical performance 4 vs. 4 plus goalkeepers.     

Validity of the Yo-Yo intermittent endurance test in young soccer players

Abstract

The Yo-Yo intermittent endurance test is frequently used to assess aerobic endurance performance in young soccer players but only the logical validity of the test has been shown to date. The main ai m of this study was to assess the criterion (i.e. association with maximal aerobic capacity, [Vdot]O_2max) and construct validities of the test in young soccer players. A secondary aim was to examine possible shared variance of the Yo-Yo intermittent endurance test with other physical capacities. Sixty-two soccer players (age 13.7±0.5 years) from an Under-14 team participated. All players performed a battery of fitness tests to assess [Vdot]O_2max, aerobic endurance performance (Yo-Yo intermittent endurance test), soccer dribbling endurance performance (Hoff dribbling test), and power performance (maximal vertical jump, 30-m sprint with 10-m split time). Results showed that the Yo-Yo intermittent endurance test was strongly correlated with [Vdot]O_2max (r=0.63, P<0.001), thereby showing the test's criterion validity. Players with the best performance on the Yo-Yo intermittent endurance test had significantly higher [Vdot]O_2max (P<0.001, large effect), and significantly better soccer dribbling endurance (P<0.001, large effect) and 30-m sprint times (P<0.05, medium effect). Logistic regression (r=0.79, P=0.0001) showed that Hoff dribbling test performance (explained variance=50.4%), [Vdot]O_2max (explained variance=39.7%), and 30-m sprint time (explained variance=14.4%) were significant independent parameters contributing to performance on the Yo-Yo intermittent endurance test. Therefore, the Yo-Yo intermittent endurance test is a valid on-field aerobic endurance performance test for young soccer players, which can also be used to differentiate the maximal aerobic capacity, soccer dribbling endurance, and 30-m sprint performance of these players.     

Fluid balance of elite Brazilian youth soccer players during consecutive days of training

In this study we investigated pre-training hydration status, fluid intake, and sweat loss in 20 elite male Brazilian adolescent soccer players (mean?±?s: age 17.2?±?0.5 years; height 1.76?±?0.05?m; body mass 69.9?±?6.0?kg) on three consecutive days of typical training during the qualifying phase of the national soccer league. Urine specific gravity (USG) and body mass changes were evaluated before and after training sessions to estimate hydration status. Players began the days of training mildly hypohydrated (USG?>?1.020) and fluid intake did not match fluid losses. It was warmer on Day 1 (33.1?±?2.4°C and43.4?±?3.2% relative humidity; P?相似文献