Testing soccer players

Different endurance characteristics of female and male german soccer players

The aims of the present study were to assess gender differences regarding lactate threshold and intermittent shuttle run performance in female and male soccer players as well as to investigate the relationships between both endurance characteristics in both genders. Fourteen female (1(st) division) and thirteen male (4(th) division) soccer players completed an incremental test (IT) to determine running velocities at 2 and 4 mmol · l(-1) blood lactate (v2 and v4) and maximum velocity (vmax) as well as an interval shuttle run test (ISRT) to determine running distance. Based on v2 and v4 and their percentages in relation to vmax, three intensity zones were calculated: a low lactate zone (<v2), a lactate accommodation zone (v2 to v4), and a lactate accumulation zone (>v4). Female soccer players have a lower v4 (8.2%), vmax (11.3%) and ISRT distance (31.6%). No gender difference was found in v2. In contrast to males, ISRT distance correlates with vmax as well as with v2 and v4 in female soccer players. The intensity zones <v2 and >v4 differ between genders. The present study revealed that gender differences increase when the running performance is intermittent including change of directions. In both genders, different relationships between lactate threshold and intermittent shuttle run performance exist. During incremental testing, the running performances of female and male players reflect different distributions of aerobic and anaerobic metabolic pathways. The revealed gender differences should be considered for soccer endurance training.

Validity of the Yo-Yo Intermittent Recovery Test Level 1 for Direct Measurement or Indirect Estimation of Maximal Oxygen Uptake in Female Soccer Players

Purpose:

To evaluate the validity of the Yo-Yo Intermittent Recovery Test Level 1 (YYIR1) for the direct assessment and the indirect estimation of maximal oxygen consumption (VO2max) in female soccer players compared with a maximal laboratory treadmill test (LTT).

Methods:

Eighteen female soccer players (21.5 ± 3.4 y, 165.6 ± 7.5 cm, 63.3 ± 7.4 kg; mean ± SD) completed an LTT and a YYIR1 in random order (1 wk apart). Their VO2max was directly measured via portable spirometry during both tests and indirectly estimated from a published non-gender-specific formula (YYIR1-F1).

Results:

The measured VO2max values in LTT and YYIR1 were 55.0 ± 5.3 and 49.9 ± 4.9 mL · kg−1 · min−1, respectively, while the estimated VO2max values from YYIR1-F1 corresponded to 45.2 ± 3.4 mL · kg−1 · min−1. Large positive correlations between the VO2max values from YYIR1 and LTT (r = .83, P < .001, 90% confidence interval = .64–.92) and YYIR1-F1 and LTT (r = .67, P = .002, .37–.84) were found. However, the YYIR1 significantly underestimated players’ VO2max by 9.4% compared with LTT (P < .001) with Bland-Altman 95% limits of agreement ranging from –20.0% to 1.4%. A significant underestimation from the YYIR1-F1 (P < .001) was also identified (17.8% with Bland-Altman 95% limits of agreement ranging from –31.8% to –3.8%).

Conclusions:

The YYIR1 and YYIR1-F1 are not accurate methods for the direct assessment or indirect estimation of VO2max in female soccer players. The YYIR1-F1 lacks gender specificity, which might have been the reason for its larger error.

Nutrient intake and food habits of soccer players: analyzing the correlates of eating practice

Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player's career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.

Evaluation of a specific reaction and action speed test for the soccer goalkeeper

The aim of this study was to develop and evaluate a new test for the soccer goalkeeper that involved perceptual and movement response components (i.e., sprint running, jumping, diving, and direction changing). The evaluation consisted of measurements in different age (U19 [18.0 ± 0.9 years], n = 21; U14 [14.1 ± 0.3 years], n = 13) and performance (i.e., first goalkeepers and substitutes) groups of goalkeepers, including measures of test-retest reliability. Validity was assessed comparing the 2 groups of goalkeepers with different expertise levels (i.e., competitive level and age group). The test-retest correlations of the reaction and action speed (RAS) test performance were significant in all single (intraclass correlation coefficient [ICC] = 0.68-0.95; p < 0.01) and complex measurements (ICC = 0.91; p < 0.01). The RAS single test performance was higher in older (U19) compared with in younger (U14) players (p < 0.001), and they also showed better results in the RAS complex tests (p = 0.000), being significantly different between the first goalkeepers and their substitutes (p = 0.001). Moreover, for all age groups (i.e., U14, U19), defensive actions to the bottom corners were faster than those to the top corners, with large ES (i.e., > 1). The major findings of the study were that the RAS test provided a reliable and valid method of assessing specific defensive agility in a group of youth soccer goalkeepers. Performance responses during the RAS test allow coaches to discriminate between age-matched goalkeepers, identify weaknesses (e.g., nonpreferred side dive performance), and to design specific training tasks.

Profile, correlation and structure of speed in youth elite soccer players

Speed, power and agility are important components of fitness and determine the level of success and performance in soccer. The aim of this study was to identify speed variables and to determine their mutual correlation and structure in youth elite soccer players. The research group consisted of players from the Czech U16 national team (n = 22, age = 15.6 ± 0.4 years). Speed variables were assessed using the following tests: a) linear speed: 5 m sprint (S5), 10 m sprint (S10) and 20 m flying sprint (F20); b) the agility: agility test 505 with turning on the dominant (A505D) and non-dominant legs (A505N) and the K-test (K) and c) ball velocity after an instep kick with the dominant (IKD) and non-dominant (IKN) legs. Significant dependence was found for S5 compared with S10, F20 vs. A505N, K vs. A505N (p < 0.01) and S10 vs. F20 (p < 0.05). The factor analysis revealed three components of the latent variable - speed. The first component consisted of linear sprint (S10, S20) and also partially consisted of maximum speed (F20). The second component was primarily composed of agility (A505D, A505N, K) and also included maximum speed (F20). The third independent component represented ball velocity after an instep kick (IKD, IKN). The speed variables in youth elite players exhibited significant heterogeneity from the perspective of performance, as determined by the monitored tests. The structure of the speed predisposition indicated that there were three components of speed. The results of our studies support the notion that each component of speed must be considered independently when designing training programmes.

Ventilatory response to exercise of elite soccer players

Background

The purpose of this study was to evaluate the role of ventilatory parameters in maximal exercise performance in elite soccer players.

Methods

From September 2009 to December 2012, 90 elite soccer players underwent evaluation of lung function test and ergospirometry by means of an incremental symptom-limited treadmill test. Results were analyzed according to i) maximal exercise velocity performed (Hi-M: high-performers, >18.65 km/h; Lo-M: low-performers, <18.65 km/h) and ii) usual role in the team.

Results

Hi-M showed higher peak minute ventilation (V˙Epeak: 158.3 ± 19.5 vs 148.0 ± 18.54 L/min, p = 0.0203), and forced expiratory volume at first second (5.28 ± 0.50 vs 4.89 ± 0.52 liters, p < 0.001) than Lo-M, independently of playing role. Moreover, a significant correlation between peak oxygen uptake and V˙E (r = 0.57, p < 0.001) was found.

Conclusions

Ventilatory response plays a role in the assessment of exercise capacity in elite soccer players.

Fitness testing of tennis players: how valuable is it?

In tennis, sport-specific technical skills are predominant factors, although a complex profile of physical performance factors is also required. The fitness test batteries assist in examining tennis players' capabilities for performance at different levels in the laboratory as well as in the field, in the junior or elite level. While laboratory tests can be, and are, used to evaluate basic performance characteristics of athletes in most individual sports, in a more specific approach, field-based methods are better suited to the demands of complex intermittent sports like tennis. A regular test battery performed at different periods of the year allows to obtain an individual's performance profile, as well as the ability to prescribe individual training interventions. Thus, the aim of the present review was to describe and evaluate the different physical tests recommended and used by practitioners, sports scientists and institutions (national tennis federations).

Performance effects of 6 weeks of aerobic production training in junior elite soccer players

This study investigates the performance effects of a 6-week biweekly anaerobic speed endurance production training among junior elite soccer players. Sixteen junior (age 16.9 ± 0.6 years) elite soccer players were tested in the Yo-Yo Intermittent Recovery test level 2 (IR2), 10-m and 35-m sprints, 7 × 35-m repeated-sprint ability (RSA) tests, countermovement jump and squat jump tests, and randomly assigned to either a control group (CG) performing their normal training schedule, which included 4 weekly soccer training sessions of approximately 90 minutes, or a training group performing anaerobic speed endurance production training twice weekly for 6 weeks in addition to their normal weekly schedule. We found that the intervention group significantly improved (p < 0.05) their performance in the Yo-Yo IR2 (63 ± 74 m) and 10-m sprint time (-0.06 ± 0.06 seconds). No significant performance changes were found in the CG. Between-group pretest to posttest differences were found for 10-m sprint times (p < 0.05). No significant changes were observed in the 35-m sprint times, RSA, or jump performances. These results indicate that short-term anaerobic production training is effective in improving acceleration and intermittent exercise performance among well-trained junior elite players.

Effects of 1 versus 2 games a week on physical and subjective scores of subelite soccer players

The physical-performance profiles of subelite male footballers were monitored during 6 wk of a competitive season. The same squad of players played either 1 (1G, n = 15) or 2 (2G, n = 15) competitive matches per week. On weeks 0, 3, and 6, 48 h postmatch, players completed countermovement jump (CMJ), 10- and 20-m sprints, the Yo-Yo Intermittent Recovery Test (YYIRT), and the Recovery-Stress Questionnaire. Both groups undertook 2 weekly training sessions. The 2G showed after 6 wk lower YYIRT (-11% to 3%, 90% CI -15.8% to -6.8%; P < .001) and CMJ performances (-18.7%, -21.6 to -15.9%; P = .007) and higher 10-m (4.4%, 1.8-6.9%; P = .007) and 20-m sprints values (4.7%, 2.9% to 6.4%; P < .001). No differences were found at 3 wk (.06 < P < .99). No changes over time (.169 < P < .611) and no differences time × group interactions (.370 < P < .550) were found for stress, recovery, and the Stress Recovery Index. In conclusion players' ability to sprint, jump, and perform repeated intense exercise was impaired when playing 2 competitive matches a week over 6 wk.

Relationship between repeated sprint ability and aerobic capacity in professional soccer players

Aim. The aim of the present study was to investigate the relationship between maximal aerobic capacity (VO_2 max) and repeated sprint ability (RSA) in a group of professional soccer players. Methods. Forty-one professional soccer players (age 23 ± 4 yrs, height 180.0 ± 5.3 cm, weight 79.6 ± 5.3 kg) were required to perform tests to assess RSA and VO_2 max on two separate days with at least 48 hr rest between testing sessions. Each player performed a treadmill test to determine their VO_2 max and a test for RSA involving the players completing 6 × 40 m sprints (turn after 20 m) with 20 s active recovery between each sprint. Results. There was a significant negative correlation between body mass normalised VO_2 max and mean sprint time (RSA_mean) (r = −0.655; P < 0.01) and total sprint time (RSA_total) (r = −0.591, P < 0.01). Conclusion. Results of the current study indicate that VO_2 max is one important factor aiding soccer players in the recovery from repeated sprint type activities.

Anthropometric profile and physical performance characteristic of the Brazilian amputee football (soccer) team

Amputee football is a variation of conventional soccer in which athletes with lower limb amputation and one athelete with upper limb amputation (the goalkeeper) participate. The objective of this study was to investigate the anthropometric and physical characteristics of amputee football athletes and to verify differences between heart rate peak (HRpeak) and equations for predicting maximum heart rate (HRmax). Twelve amputee soccer players from the Brazilian team participated in this study. The body mass, height and body composition were measured. The physical tests used were: the 20 m running test, the T-square test and the Yo Yo intermitent recovery test - level 1 (YYIRT1). The percentage of fat was significantly different between midfielders and defenders. No significant differences were found between positions in the physical tests. The HRpeak was significantly lower than all of HRmax prediction equations tested. We conclude that the indicators of physical performance did not differ significantly between the different tactics roles of players, and that, after intermittent maximum effort, the cardiac response was lower when compared with the investigated HRmax prediction equations.

Yo-Yo intermittent recovery test performances within an entire football league during a full season

The study examined Yo-Yo intermittent recovery level 2 (YYIR2) and submaximal YYIR1 test performances in 172 male semi-professional football players (age; 25.8 ± 4.1 years) representing all teams in a top league at pre-season, start-season, mid-season and end-season. YYIR2 performance was 847 ± 227 m (±SD) at pre-season and rose (P < 0.05) by 128 ± 113 m to 975 ± 205 m at start of season and further (P < 0.05) by 59 ± 102 m to 1034 ± 211 m at mid-season. Submaximal YYIR1 HR was 90.9 ± 4.2% HR(max) at pre-season, which was higher (P < 0.05) than at start, mid and end of season (87.0 ± 3.9, 85.9 ± 4.1 and 87.0 ± 3.7% HR(max), respectively). Peak YYIR2 performance and minimum YYIR1 HR were 1068 ± 193 m and 85.1 ± 3.8% HR(max), respectively, with ~50% of the players peaking at mid-season. Top-teams and middle-teams had higher (P < 0.05) peak YYIR2 scores (1094 ± 205 and 1121 ± 152 m, respectively) than bottom-teams (992 ± 185 m). YYIR2 performance was 16% higher (P < 0.05) and YYIR1 HR was 1.4% HR(max) lower (P < 0.05) for regular players than non-regular players at pre-season and remained lower (P < 0.05) throughout the season. Central defenders had poorer (P < 0.05) YYIR performances compared to other positional roles. In conclusion, YYIR performances are highly variable within a football league over a season and are influenced by league ranking, regularity of competitive play and playing position.

Reliability and validity of the soccer specific INTER field test

The aims of this study were to explain how the Intermittent Endurance Running (INTER) test is executed, describe physiological responses during testing, and evaluate reliability and content validity in this new soccer specific test. The test consists of 20 m shuttle running, interspersed with straight sprints, agility sprints, walking and resting. Shuttle run speed is increased at each level until exhaustion. Thirteen male professional players participated in the present study. Exercise tolerance time, distance covered, mean blood lactate and mean heart rate were 25:51 ± 2:41 min, 2892 ± 324 m, 5.5 ± 1.2 mmol · L(-1) and 161 ± 11 beats · min(-1), respectively, during the INTER test. Sprint and agility performance decreased significantly at higher levels. Eight of the players performed a retest for reliability evaluations. Mean difference ± 95% limits of agreement, coefficient of variation (CV) and intraclass correlation coefficient (ICC) for exercise tolerance time between test and retest were -00:41 ± 02:25 min, 2.5% and 0.75, respectively. The CV for sprint and agility performance between test and retest was <1%. The INTER test mimics soccer games on distance/time ratio, frequency of sprints, heart rate and blood lactate values, and could be an alternative field test for evaluating essential physical performance aspects in soccer players.

Short-term training effects of vertically and horizontally oriented exercises on neuromuscular performance in professional soccer players

PURPOSE

The aim of this study was to compare the effects of 2 strength and conditioning programs involving either purely vertically oriented or combining vertically and horizontally oriented exercises on soccer-relevant performance variables (ie, acceleration, jumping ability, peak power, and endurance).

METHODS

Twenty-two professional male soccer players were randomly assigned to 2 training groups: vertical strength (VS, n = 11) and vertical and horizontal strength (VHS, n = 11). Players trained 2 times per week during all the preseason (5 wk) and 3 weeks of the competitive season. The effect of the training protocols was assessed using double-and single-leg vertical countermovement jumps (CMJ), half-squat peak power (PP), sprint performance over 5 and 15 m, and blood lactate concentration at selected running speeds.

RESULTS

Both groups obtained significant improvements in PP (P < .05; ES = 0.87 and 0.80 for VS and VHS, respectively) and small practical improvements in 5-m- (P < .05; ES = 0.27 and 0.25 for VS and VHS, respectively) and 15-m-sprint time (P < .05; ES = 0.19 and 0.24 for VS and VHS, respectively). The CMJ performance showed a small improvement (P < .05, ES = 0.34) only in the VHS group. Submaximal aerobic-fitness changes were similar in both groups (P < .05; ES = 1.89 and 0 .71 for VS and VHS, respectively).

CONCLUSION

This study provided a small amount of practical evidence for the consideration of preseason training protocols that combine exercises for vertical- and horizontal-axis strength development in professional male soccer players. Further studies using more aggressive training protocols involving horizontally oriented conditioning exercises are warranted.

Distribuição de subgrupos com base nas respostas fisiológicas em jogadores profissionais de futebol pela técnica K Means Cluster

INTRODUÇÃO: A preparação física no futebol necessita estar sempre em constante atualização em virtude das exigências presentes no futebol contemporâneo. OBJETIVO: Verificar a sensibilidade da técnica estatística K Means Cluster na distribuição de grupos com base nas respostas fisiológicas pertinentes ao futebol. MÉTODOS: Os atletas foram submetidos a avaliações antropométricas para determinar o percentual de gordura (%G) e de massa magra (MM), teste incremental em esteira para obter o VO2 máximo (VO2máx) e a velocidade de limiar ventilatório (VLim), bem como testes de campo para a agilidade (AG) e o salto vertical (SV). Os dados foram analisados pelo teste de Kruskal-Wallis e a distribuição dos grupos foi desenvolvida pela técnica de K Means Cluster conforme as semelhanças dos jogadores com essas variáveis fisiológicas, assumindo o nível de significância de p < 0,05. RESULTADOS: Os grupos diferiram significativamente somente com relação ao SV (p < 0,001), MM (p < 0,001), VLim (p = 0,011) e VO2máx (p = 0,029) indicando que para estas variáveis, os atletas necessitam ser distribuídos em grupos. Entretanto, o %G e a AG (p = 0,317; p = 0,922), respectivamente, não foram diferentes, indicando que essas variáveis podem ser aprimoradas em todos os atletas de maneira coletiva. CONCLUSÃO: Tendo em vista os resultados encontrados, podemos concluir que a distribuição dos grupos pela técnica K Means Cluster pode ser realizada utilizando as respostas fisiológicas dos atletas no intuito de otimizar e priorizar o treinamento físico das principais necessidades apresentadas em comum pelos atletas, independentemente da função tática exercida em campo.

The development of aerobic and skill assessment in soccer

Methods of assessing soccer players' performance have developed significantly in recent times. The fitness profiles and skill levels of a prospective elite soccer player is a valuable resource for coaches in the process of identifying talent. Traditional means to measure aerobic fitness have centred on the 'aerobic capacity' or '&OV0312;O(2max)' test (also known as the maximal oxygen consumption test) but, over time, this has been shown not to be a sensitive measure for specific aspects of soccer in a match situation. Therefore, numerous soccer-specific simulations have been designed to re-create exercise patterns similar to those experienced during a match. Some of these studies have yet to be validated, while others have been shown to result in a similar physiological load to that encountered during regular match play. Further developments have led to specifically designed intermittent sprint tests, which are used as a sensitive tool to accurately measure the fluctuations in players' ability both between and within soccer seasons. Testing procedures have also been developed that incorporate elements of both skill and physical ability. Soccer-specific field tests have been designed, incorporating skill and dynamic movements, and this opens up the possibility of teams testing the aerobic capacity of their elite players using soccer-specific movements. Valid studies assessing soccer-specific skills in an ecologically sound environment have been quite rare until recently. Some test protocols have been deemed largely irrelevant to soccer match play, while others have had limited impact on scientific literature. More recently, skill tests have been developed and shown to be valid and reliable methods of assessing soccer skill performance. Many new skill tests continue to be developed, and some have been shown to be highly reliable, but further study of these relatively novel concepts is required before a more solid recommendation can be made. Overall, while significant work has been completed to date, there is still a need for further focused investigations, which can more closely assess the physiological demands of an elite soccer player, with a particular emphasis on sport-specific exercises during the execution of soccer skills. In this regard, more reliable and specific performance tests can be designed to more efficiently assess soccer players in the future.

Effect of training on physiological and biochemical variables of soccer players of different age groups

Purpose

To find out the effect of training on selected physiological and biochemical variables of Indian soccer players of different age groups.

Methods

A total of 120 soccer players volunteered for the study, were divided (n = 30) into 4 groups: (i) under 16 years (U16), (ii) under 19 years (U19), (iii) under 23 years (U23), (iv) senior (SR). The training sessions were divided into 2 phases (a) Preparatory Phase (PP, 8 weeks) and (b) Competitive Phase (CP, 4 weeks). The training program consisted of aerobic, anaerobic and skill development, and were completed 4 hrs/day; 5 days/week. Selected physiological and biochemical variables were measured at zero level (baseline data, BD) and at the end of PP and CP.

Results

A significant increase (P < 0.05) in lean body mass (LBM), VO_2max, anaerobic power, grip and back strength, urea, uric acid and high density lipoprotein cholesterol (HDL-C); and a significant decrease (P < 0.05) in body fat, hemoglobin (Hb), total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterol (LDL-C) were detected in some groups in PP and CP phases of the training when compare to BD. However, no significant change was found in body mass and maximal heart rate of the players after the training program.

Conclusion

This study would provide useful information for training and selection of soccer players of different age groups.

Aerobic capacities and anthropometric characteristics of elite female soccer players

Ingebrigtsen, J, Dillern, T, and Shalfawi, SAI. Aerobic capacities and anthropometric characteristics of elite female soccer players. J Strength Cond Res 25(12): 3352-3357, 2011-This study investigated aerobic capacities and anthropometric characteristics within a group of 29 elite female soccer players. The purpose was to identify and establish aerobic capacities and anthropometric characteristics for these players and to look for possible positional differences between keepers, defenders, midfielders, and attackers. We did this by measuring standard anthropometrical variables and maximal oxygen (VO(2)max) and anaerobic threshold (AT). One-way analysis of variance revealed no significant differences among anthropometric or physiological variables. However, a trend (p = 0.062) toward positional differences was found within running speed at AT. A subsequent Tukey post hoc test showed differences (p = 0.04) between keepers and defenders, with the latter running faster (∼1.7 km·h) at AT. The present results suggest that few anthropometric and physiological differences exist between playing positions in elite female soccer players. Furthermore, the current results indicate that present elite players' physiological characteristics are similar to those previously shown, despite the rapid changes of the female soccer game. Based on well-established knowledge that different playing positions within a soccer team ought to have distinct capacities, we recommend regular testing programs to be able to construct and implement tailored training programs for players' physical capacities with respect to the demands of their playing positions.

Is there a relationship between the playing position of soccer players and their food and macronutrient intake?

Many authors have proposed the necessity of the design and implementation of dietary and nutrition education programs for soccer players, although little information is available about the determinants of food selection and nutrient intake. The aim of this study was to evaluate the nutritional intake and eating patterns of soccer players according to their playing position in the team. Eighty-seven young male soccer players (aged 16-21 years) were recruited from the junior teams of a Spanish First Division Soccer League Club and divided into 6 positional categories (goalkeepers, full-backs, centre-backs, midfielders, wingers, and forwards). Body composition (height, weight, and body fat), performance in soccer-specific tests (jumping, sprinting, and intermittent endurance), and dietary intake (weighed food intake method) were assessed. A spontaneous higher carbohydrate intake was observed for full-backs, midfielders, and wingers (g·kg(-1) body mass: 4.9 ± 1.0, 4.9 ± 1.3, 4.9 ± 0.8; % of energy intake: 47 ± 5, 46 ± 6, 46 ± 4), compared with goalkeepers and centre-backs (g·kg(-1) of body mass: 3.9 ± 1.0, 4.3 ± 1.1; % of energy intake: 44 ± 3, 42 ± 4). These differences were related to food selection patterns, and a higher contribution to daily energy intake of cereals, derivatives, and potatoes was observed between full-backs compared with goalkeepers and centre-backs (33% vs. 27% and 25%). The magnitude of these differences is limited considering the whole diet, and an inadequate nutrient intake were observed in most individuals of every group. The design and implementation of nutrition intervention programs, taking into consideration positional differences in nutritional intake, would be useful for these players.

Coordination of soccer players during preseason training

This study aimed to verify whether coordination improves as a result of a preseason soccer training. During 5 experimental sessions (days 1, 6, 11, 15, and 19), 16 semiprofessional male soccer players (22.0 ± 3.6 years) were administered 3 specific soccer tests (speed dribbling, shooting a dead ball, and shooting from a pass) and an interlimb coordination test (total duration of a trial: 60 seconds), consisting of isodirectional and nonisodirectional synchronized (1:1 ratio) hand and foot flexions and extensions at an increasing velocity of execution (80, 120, and 180 b·min(-1)). Furthermore, subjective ratings were monitored to assess the recovery state (RestQ) of the players, their perceived exertion (rating of perceived exertion [RPE]) for the whole body, and the perceived muscle pain (rating of muscle pain [RMP]) for the lower limbs and the internal training load by means of the session-RPE method. The ratios between post and pretraining RPE and RMP increased only during the first 2 experimental sessions and decreased after the second week of the training camp (p = 0.001). The Rest-Q showed increases (p < 0.05) for general stress, conflict/pressure, social recovery, and being in shape dimensions. Conversely, decreases (p < 0.05) were observed for social stress, fatigue, physical complaints dimensions. Throughout the preseason, the players improved their speed dribbling (p = 0.03), Shooting from a Pass (p = 0.02), and interlimb coordination (p < 0.0001) performances. These coordination tests succeeded in discriminating coordination in soccer players and could integrate field test batteries during the whole soccer season, because they were easily and inexpensively administrable by coaches.

Individual match playing time during the season affects fitness-related parameters of male professional soccer players

The purpose of this study was to analyze the effects of an entire season on physical fitness parameters (PFPs) in male professional soccer players (N = 18). Performance in 5- and 30-m sprint (T5 and T30), countermovement jump (CMJ), agility (T-test), knee extensor (KE) and knee flexor (KF) isokinetic strength, hamstrings/quadriceps strength ratio (H/Q) and bilateral differences (BDs), and Yo-Yo intermittent endurance test 2 (YYIE2) was evaluated in 4 moments (E1-E4) throughout the season. Individual match playing time was quantified. Significant improvements in CMJ and YYIE2 from E1 to E2 were observed (p < 0.05-0.01). The T30 improved from E2 to E3 (p < 0.01). The CMJ decreased from E2 to E3 and E4, and YYIE2 from E2 to E4 (p < 0.05). There were increments in the H/Q ratio and Agility from E1 and E2 to E3 and E4 (p < 0.05-0.01). Significant correlations were found in all evaluation points between different PFPs and between changes in strength parameters and agility, T5 and T30, CMJ, and YYIE2 (p < 0.05-0.001). Influence of individual match playing time was correlated to changes in T5 (E1 to E3; r = -0.705), KE nondominant leg (KEND; E2 to E3; r = 0.786), and KF (E3 to E4; r = 0.575-0.590). The interrelationship between muscle strength (e.g., KE), sprint (e.g., T5), and jump abilities (CMJ) suggests the importance of muscle strength and power training for soccer. This study suggests that the systematic participation of the players in soccer matches favors the increase and maintenance of soccer players KE and KF muscle strength and sprint ability (T5). Thus, given the unique demands of actual match play, coaches should try to incorporate a competitive friendly match in the weekly training cycle of nonstarter players.

Analysis of repeated high-intensity running performance in professional soccer

The aims of this study were twofold: (1) to characterize repeated high-intensity movement activity profiles of a professional soccer team in official match-play; and (2) to inform and verify the construct validity of tests commonly used to determine repeated-sprint ability in soccer by investigating the relationship between the results from a test of repeated-sprint ability and repeated high-intensity performance in competition. High-intensity running performance (movement at velocities >19.8 km · h(-1) for a minimum of 1 s duration) was measured in 20 players using computerized time-motion analysis. Performance in 80 French League 1 matches was analysed. In addition, 12 of the 20 players performed a repeated-sprint test on a non-motorized treadmill consisting of six consecutive 6 s sprints separated by 20 s passive recovery intervals. In all players, most consecutive high-intensity actions in competition were performed after recovery durations ≥61 s, recovery activity separating these efforts was generally active in nature with the major part of this spent walking, and players performed 1.1 ± 1.1 repeated high-intensity bouts (a minimum of three consecutive high-intensity bouts with a mean recovery time ≤20 s separating efforts) per game. Players reporting lowest performance decrements in the repeated-sprint ability test performed more high-intensity actions interspersed by short recovery times (≤20 s, P < 0.01 and ≤30 s, P < 0.05) compared with those with higher decrements. Across positional roles, central-midfielders performed more high-intensity actions separated by short recovery times (≤20 s) and spent a larger proportion of time running at higher intensities during recovery periods, while fullbacks performed the most repeated high-intensity bouts (statistical differences across positional roles from P < 0.05 to P < 0.001). These findings have implications for repeated high-intensity testing and physical conditioning regimens.

Angiotensin-converting enzyme/vitamin D receptor gene polymorphisms and bioelectrical impedance analysis in predicting athletic performances of Italian young soccer players

We evaluated the association between 2 genetic polymorphisms known to be involved in fitness and performance, and anthropometric features, body composition, and athletic performances in young male soccer players with the goal of identifying genetic profiles that can be used to achieve maximal results from training. One hundred twenty-five medium-high-level male soccer players were genotyped for angiotensin-converting enzyme (ACE) I/D, and vitamin D receptor (VDR) FokI gene polymorphisms and scored for anthropometric measurements, body composition, and athletic performance. Body mass index, fat mass, fat-free mass, resistance, reactance, impedance, phase angle (PA), and body cell mass were measured. Athletic performance was evaluated by squat jump, countermovement jump (CMJ), 2-kg medicine ball throw, 10- and 20-m sprint time. We observed that the homozygous ff genotype of the VDR gene was significantly more represented in young soccer players than in a matched sedentary population. Values of reactance and PA were differently distributed in ACE and VDR genotypes with high mean values in subjects with DD (ACE) and FF (VDR) genotypes. No correlation was observed between ACE or VDR genotypes and 2-kg medicine ball throw, 10- and 20-m sprint times. The ID genotype of ACE was associated with the best performances in squat jump and CMJ. Our results suggest that determination of ACE and VDR genotypes might help select those young athletes harboring the most favorable genetic potential to succeed in soccer.

Yo-Yo IR2 test e teste de margaria: validade, confiabilidade e obtenção da frequência cardíaca máxima em jogadores jovens de futebol

Os objetivos do presente estudo foram: i) avaliar a validade de constructo do Yo-Yo Intermittente Recovery Test Level 2 (Yo-Yo IR2) e do teste de Margaria (TM) com o desempenho em alta intensidade de exercício durante jogos oficiais em jogadores de futebol; ii) verificar a confiabilidade (teste-reteste) dos dois testes; iii) comparar os valores da frequência cardíaca máxima (FCM) obtida nesses protocolos e em jogo. Dezoito jogadores (média ± DP; idade 14 ± 0,8 anos, estatura 172 ± 9cm, peso 64,3 ± 8,5kg) pertencentes à mesma equipe foram avaliados em teste-reteste nos referidos protocolos e no percentual de tempo de permanência acima de 85% da FCM individual (PTP>85%FCM) em dois jogos oficiais do Campeonato Mineiro Infantil. Uma alta correlação foi encontrada entre o desempenho no Yo-Yo IR2 e PTP>85%FCM (rs = 0,71; p < 0,05). Não houve correlação estatisticamente significante entre o desempenho no TM e PTP>85%FCM (rs = 0,44; p = 0,06). O Yo-Yo IR2 se mostrou mais variável e menos reprodutível (CV = 11%; CCI [95% IC] = 0,38) do que TM (CV = 1%; CCI [95% IC] = 0,93). O maior valor de FCM (p < 0,001) ocorreu no jogo (202 ± 8bpm). A FCM no Yo-Yo IR2 (194 ± 4bpm) foi menor (p < 0,006) do que TM (197 ± 6bpm). Conclui-se que o Yo-Yo IR2 pode ser considerado mais válido para predizer a manutenção de alta intensidade de exercício em jogo que é uma importante medida de desempenho no futebol. Porém, há necessidade de padronização rigorosa entre os procedimentos de avaliação para estabilidade da medida. A FCM deve ser observada em diversas situações, principalmente competitiva, para possibilitar que ocorra o maior valor individual.

Sprinting analysis of elite soccer players during European Champions League and UEFA Cup matches

It has been suggested that assessment of high-intensity activities during a match is a valid measure of physical performance in elite soccer. Recently, sprinting activities have been analysed in more depth. The aim of this study was to develop a detailed analysis of the sprinting activities of different playing positions during European Champions League and UEFA Cup competitions. Altogether, 717 elite outfield soccer players were evaluated throughout 2002-2006 using ProZone® (Leeds, UK). Sprinting (explosive and leading) was analysed for each playing position. To compare positional differences, a Kruskal-Wallis analysis was performed. Differences were found among positions for total number of sprints and total sprint distance covered: wide midfielders > (attackers = wide defenders) > central midfielders > central defenders (P < 0.001), as well as for explosive sprints: (wide midfielders = attackers = wide defenders) > central defenders, wide midfielders > central midfielders > central defenders and attackers = wide defenders = central midfielders (P < 0.001), and leading sprints: wide midfielders > (attackers = wide defenders) > central midfielders > central defenders (P < 0.001). For each group, there were no differences in ratio of explosive to leading sprints. Wide midfielders performed a higher number of sprints in all five distance categories than all other positions. This study showed that sprinting characteristics are influenced by position. Wide midfielders have to complete additional high-intensity activities during training sessions compared with the other positions to achieve the performance level required during the match.

Relationship between the 20-m multistage shuttle run test and 2 soccer-specific field tests for the assessment of aerobic fitness in adult semi-professional soccer players

The aim of this study was to examine the relationship of 2 different field tests for the assessment of aerobic fitness in soccer players with the multistage 20-m test used for the evaluation of maximum oxygen uptake. Nineteen semi-professional male soccer players (age: 22.8 ± 2.5 mean ± SD) performed, under similar conditions, 3 field tests in a counterbalanced order 7 days apart. These tests were the multistage 20-m shuttle run test (MSRT), the Bangsbo test, and the Hoff test. Heart rate was recorded in all tests with telemetry, and the Borg scale was introduced at the end of exercise. Finally, 3-minute post-test lactate concentration was determined. Performance was 11.2 ± 0.9 levels in the MSRT, 1,658.9 ± 119.9 m in the Bangsbo test, and 1,798.2 ± 125.9 m in the Hoff test. There was a significant correlation between the Hoff test and performance in the MSRT (r = 0.49, p < 0.05). The Bangsbo test was not associated with the MSRT score (r = 0.26, p > 0.05). The maximum heart rate achieved in the Bangsbo test was significantly lower compared with that in the MSRT and Hoff test (Bangsbo: 186.6 ± 9.6, Hoff: 192 ± 7.6, MSRT: 190.4 ± 9.3 beats/min, p < 0.05). No difference was found in post-test lactate concentration among the 3 tests. In conclusion, the Hoff test can be used for the assessment of endurance in adult semi-professional soccer players. Coaches and teams could benefit from using the Hoff test that resembles soccer actions for the assessment of players' aerobic fitness.

Measuring soccer skill performance: a review

The ability to execute skilled movement patterns efficiently and effectively is the most important aspect of soccer performance and players must apply cognitive, perceptual and motor skills to rapidly changing situations. There have been attempts to measure these parameters for talent identification (or development) purposes and skill acquisition and intervention research; the aim of this review is to examine the strengths and limitations of these tests. High levels of perceptual and cognitive skill are characteristics of those players who are able look in the right places for information and process this information efficiently before deciding on a suitable course of action. The motor skills required to successfully control, pass, dribble and shoot the ball at goal are fundamental skills of the soccer player and a variety of methods have been used to measure these aspects. The tests mentioned in this review vary in their complexity and the type of skill(s) they purport to measure. The assessment of choice must come down to a number of factors including cost, available time and space, number of athletes in the cohort and experience of researchers. Furthermore, consideration must be given to the aim(s) of the research/assessment and issues relating to validity and reliability.

Sub-maximal and maximal Yo-Yo intermittent endurance test level 2: heart rate response, reproducibility and application to elite soccer

The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2 test), (2) assess the relationship between the Yo-Yo IE2 test and match performance and (3) quantify the sensitivity of the Yo-Yo IE2 test to detect test-retest changes and discriminate between performance for different playing standards and positions in elite soccer. Elite (n = 148) and sub-elite male (n = 14) soccer players carried out the Yo-Yo IE2 test on several occasions over consecutive seasons. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance and heart rate after 6 min were 3.9% (n = 37) and 1.4% (n = 32), respectively. Elite male senior and youth U19 players Yo-Yo IE2 performances were better (P < 0.01) than elite youth U16s and sub-elite players (2,603 ± 451 and 2,534 ± 549 vs. 1,855 ± 535 vs. 1,749 ± 382 m). The intra- and inter-season CV for Yo-Yo IE2 test performance were 4.2 and 5.6%, respectively. A correlation was observed (P < 0.05) between Yo-Yo IE2 test performance and the total (r = 0.74) and high-intensity (r = 0.58) running distance covered in a match. A correlation was also evident (P < 0.01) between Yo-Yo IE2 test heart rate after 6 min expressed in percentage of maximal heart rate and the peak values for high-intensity running performed by midfielders in 5-min (r = -0.71), 15-min (r = -0.75) and 45-min periods (r = -0.77). The present data demonstrate that the Yo-Yo IE2 test is reproducible and can be used to determine the capacity of elite soccer players to perform intense intermittent exercise. Furthermore, the Yo-Yo IE2 test was shown to be a sensitive tool that not only relates to match performance but can also differentiate between intermittent exercise performance of players in various standards, stages of the season and playing positions.

An investigation into the effects of different warm-up modalities on specific motor skills related to soccer performance

The aim of this study was to investigate the effect of different warm-up stretch modalities on specific high-speed motor capabilities important to soccer performance. Twenty-seven male soccer players performed 3 warm-up conditions, active warm-up (WU), WU with static stretching (SPS), and WU with dynamic stretching (ADS). Heart rate, countermovement jump, 20-m sprint, and Balsom agility tests were performed after each intervention. Vertical jump heights were significantly greater (p < 0.01) in the WU and ADS conditions compared to those in the SPS trial. The 20-m sprint and agility times showed that the SPS condition was significantly slower (p < 0.01) than the WU and ADS conditions, with the ADS trial being significantly faster (p < 0.05) than the WU condition. Heart rate was significantly higher (p < 0.01) for participants post-WU and -ADS trials compared to the SPS condition. These findings suggest that the superior performance of the dynamic stretch and warm-up-only conditions compared to the static stretch condition may be linked to increases in heart rate. The reasons for the dynamic stretch trial superiority compared to the warm-up condition are less clear and as yet to be established. We recommend for optimal performance, specific dynamic stretches be employed as part of a warm-up, rather than the traditional static stretches.

The yo-yo test: reliability and association with a 20-m shuttle run and VO(2max)

PURPOSE

The purpose of the study was to determine the reliability of yo-yo intermittent recovery test (yo-yo) scores and their degree of association with a 20-m shuttle run (20MSR) and VO(2max) values.

METHODS

Subjects were elite (Australian Football League [AFL], n = 23), state-level (hockey, n = 15, and cricket, n = 27), and recreational team-sport players (n = 33). All performed a 20MSR and the yo-yo at either level 1 (recreational and state level) or level 2 (AFL). A recreational subgroup (n = 19) also performed a treadmill VO(2max) test.

RESULTS

Test-retest results found the yo-yo (levels 1 and 2) to be reliable (ICC = .86 to .95). The 20MSR and yo-yo level 1 scores correlated (P < .01) in the recreational (r = .81 to .83) and state-level groups (r = .84 to .86), and 20MSR and yo-yo level 2 scores, in the elite (r = .86) and recreational groups (r = .55 to .57). The VO(2max) and yo-yo level 1 scores in the recreational group correlated (P < .01, r = .87), but no association was found with yo-yo level 2 (r = .40 to .43, nonsignificant).

CONCLUSIONS

We conclude that level 1 (recreational and state level) and level 2 (elite) yo-yo scores were both strongly associated with 20MSR scores and VO(2max) (level 1: recreational subjects only). The yo-yo appears to measure aerobic fitness similarly to the 20MSR but may also be used as a field test of the ability to repeat high-intensity efforts.

In-season effect of short-term sprint and power training programs on elite junior soccer players

The aim of this study was to examine the effects of 2 in-season short-term sprint and power training protocols on vertical countermovement jump height (with or without arms), sprint (Sprint-15m) speed, and agility (Agility-15m) speed in male elite junior soccer players. Twenty highly trained soccer players (age 18.3 +/- 0.6 years, height 177 +/- 4 cm, body mass 71.4 +/- 6.9 kg, sum skinfolds 48.1 +/- 11.4 mm), members of a professional soccer academy, were randomly allocated to either a CONTRAST (n = 10) or SPRINT (n = 10) group. The training intervention consisted of 6 supervised training sessions over 7 weeks, targeting the improvement of the players' speed and power. CONTRAST protocol consisted of alternating heavy-light resistance (15-50% body mass) with soccer-specific drills (small-sided games or technical skills). SPRINT training protocol used line 30-m sprints (2-4 sets of 4 x 30 m with 180 and 90 seconds of recovery, respectively). At baseline no difference between physical test performance was evident between the 2 groups (p > 0.05). No time x training group effect was found for any of the vertical jump and Agility-15m variables (p > 0.05). A time x training group effect was found for Sprint-15m performance with the CONTRAST group showing significantly better scores than the SPRINT group (7.23 +/- 0.18 vs. 7.09 +/- 0.20 m.s, p < 0.01). In light of these findings CONTRAST training should be preferred to line sprint training in the short term in young elite soccer players when the aim is to improve soccer-specific sprint performance (15 m) during the competitive season.

Interrelationships between measured running intensities and agility performance in subelite rugby union players

The purpose of this study was to investigate agility performance of rugby players using various intensity running tests. A further aim was to investigate if any differences existed between playing positions in relation to agility performance. Nineteen subelite players (mean +/- SD age, 23.0 +/- 5.4 years) participated in the study. Players underwent measurements of anthropometry (height, body mass, and sum of four skinfolds). Running tests investigated were speed (10 m and 40 m sprint), agility (T Test and Illinois), and multistage fitness tests (20 m, 10 m, and 5 m), with all tests for agility measured against the Illinois agility test. Results indicated that backline players produced significant correlations (P < 0.05) in agility compared with forwards. The findings indicate that developing or using existing rugby-specific agility programs to aid performance may be of greater benefit and of higher priority in training programs designed for backs rather than forwards.

Efeito ergogênico de uma bebida esportiva cafeinada sobre a performance em testes de habilidades específicas do futebol

O consumo de cafeína tem demonstrado promover efeitos ergogênicos sobre a performance de atletas de esportes coletivos. O objetivo do presente estudo foi comparar o efeito de uma bebida esportiva cafeinada (BEC) frente a uma bebida carboidratada comercial (BCC) sobre a performance durante a execução de testes físico-motores de habilidades específicas do futebol. Os atletas foram submetidos a dois testes, salto vertical (Sargent Jump) e teste de agilidade (Illinois Agility Test), que foram executados antes e após as partidas durante as quais foram consumidas BEC (7% de carboidratos (CHO), concentração de cafeína correspondente a 250mg.l-1) ou BCC (sem cafeína, 7% de CHO). Os resultados demonstraram que BEC aumentou significantemente (p < 0,01) a altura atingida no salto em relação ao momento anterior ao seu consumo e em comparação com a BCC (p = 0,02). BCC não promoveu aumento na potência de membros inferiores. Tanto BEC (p = 0,62) quanto BCC (p = 0,93), não aumentaram a agilidade no teste realizado após a partida em comparação com o realizado anteriormente. Ambas as bebidas não foram capazes de melhorar o desempenho na execução do teste de agilidade após a partida (p = 0,95). O consumo de BEC proporcionou um efeito ergogênico para jogadores de futebol, aumentando a potência de membros inferiores relacionada com a força explosiva. Contudo, quanto à agilidade não foi possível identificar vantagens no desempenho.