The effects of game types on intensity of small-sided games among pre-adolescent youth football players.

The aim of this study was to examine the effects of variations in pitch dimensions on pre-adolescent youth soccer players' physiological responses during two different types of small-sided games (SSG). Sixteen young soccer players (age: 13.2 ± 0.6 years; body mass: 52.5 ± 7 kg; height: 163.4 ± 6 cm) participated in this study. They performed 4 vs. 4 stop-ball SSG (SB-SSG) vs. small-goals SSG (SG-SSG) with 4×4 min and 2 min of passive recovery in between, using 3 different pitch sizes (small: 10×15, medium: 15×20, and large: 20×25 m). Heart rate (HR), lactate concentration ([La-]), and rating of perceived exertion (RPE) were measured during each session. The results show that SB-SSG induced higher HR responses than SG-SSG for the 3 pitch sizes: for HR (167.2±3.0 vs. 164.5±3.0, 172.3±2.9 vs. 169.2±3.1, and 175.4±3.1 vs. 171.1±2.7 bpm; P<0.05, for small, medium, and large, respectively) and [La-] (7.1±1.0 vs. 6.5±1.04, 7.3±1.0 vs. 6.8±1.2, and 7.8±0.9 vs. 7.1±0.8 mmol·l-1; P<0.05 on small, medium, and large pitches, respectively), whereas RPE scores were significantly higher during SB-SSG compared to SG-SSG (6.2±1.0 vs. 5.8±0.9; P<0.05, respectively) on the small pitch. In the present study higher physiological responses were observed in SSG in pre-adolescent young soccer players when using the stop-ball conditions in comparison with the small-goal rule for all pitch sizes - small, medium, and large. Stop-ball conditions in comparison with the small-goal rule for all pitch sizes - small, medium, and large.

Soccer small-sided games in young players: rule modification to induce higher physiological responses.

The aim of this study was to identify the physiological responses of 3 forms of players' numbers during two different games rules of small-sided games (SSG: stop-ball vs. small-goals rules). Eighteen youth amateur soccer players (age 13.5±0.7 years; height 168.9±6.1cm; body mass 63.1±7.7 kg) participated in this study and performed 3 SSGs with varying players' number (2vs.2; 3vs.3 and 4vs.4): stop-ball SSG (SB-SSG) vs. small-goals SSG (SG-SSG) in a randomized and counter-balanced order on a constant pitch dimension (20×25m). The players performed 4×4 min SSG with 2-min of passive recovery in-between. Heart rate (HR), (expressed in bpm and % HRmax), lactate ([La-]), and rating of perceived exertion (RPE) were collected during each session. SB-SSG induced the higher HR values in comparison with the SG-SSG for the 3 game formats (2vs.2; 3vs.3 and 4vs.4). Also, compared with SG-SSG, SB-SSG induced the higher HR values during 2vs.2 compared with 4vs.4 games rules (178 vs. 174 and 175 vs. 171 bpm, respectively). However, the SB-SSG was more intense compared with SG-SSG in the 2 vs. 2 game rule compared with the two others (3 vs.3 and 4 vs. 4) for [La-] and RPE (7.58 vs. 7; 7.25 vs. 6.75 and 6.5 vs. 6.16 mmol ∙ L-1, and 7.75 vs. 7.33; 7.41 vs. 7.08 and 7.16 vs. 6.83, respectively). Therefore, the use of 2 vs. 2 and 3 vs. 3 SSG with SB-SSG seems to represent an alternative to coaches to increase cardiovascular and metabolic demands in youth soccer players.

Diaphyseal tibiofibular synostosis in professional athletes: Report of 2 cases.

Anterior leg pain is common in professional athletes and tibiofibular synostosis is reported to be a rare cause of anterior compartment pain or ankle pain related to sports activities. The management and appropriate treatment of this condition in professional athletes is controversial and the literature on the topic is sparse. Distal synostosis is usually related to ankle sprain and syndesmotic ligament injury, and proximal synostosis has been linked to leg length discrepancy and exostosis. Mid-shaft synostosis is even less common than proximal and distal forms. We present the treatment of mid-shaft tibiofibular synostosis in 2 cases of professional athletes (soccer and basketball player), along with a review of the literature. When diaphyseal synostosis is diagnosed, first-line conservative treatment, including ultrasound-guided steroid injection is recommended. However, if it does not respond to conservative management, surgical resection may be indicated to relieve symptoms.

Anthropometric and physiological characteristics of Melanesian futsal players: a first approach to talent identification in Oceania.

This study assessed the anthropometric and physiological characteristics of elite Melanesian futsal players in order to determine the best performance predictors. Physiological parameters of performance were measured in 14 Melanesian (MEL-G, 24.4±4.4 yrs) and 8 Caucasian (NMEL-G, 22.9±4.9) elite futsal players, using tests of jump-and-reach (CMJ), agility (T-Test), repeated sprint ability (RSA), RSA with change-of-direction (RSA-COD), sprints with 5 m, 10 m, 15 m, and 30 m lap times, and aerobic fitness with the 30-15 intermittent fitness test (30-15 IFT). The anthropometric data revealed significantly lower height for MEL-G compared with NMEL-G: 1.73±0.05 and 1.80±0.08 m, respectively; P = 0.05. The CMJ was significantly higher for MEL-G than NMEL-G: 50.4±5.9 and 45.2±4.3 cm, respectively; P = 0.05. T-Test times were significantly lower for MEL-G than NMEL-G: 10.47±0.58 and 11.01±0.64 seconds, respectively; P = 0.05. MEL-G height was significantly related to CMJ (r = 0.706, P = 0.01), CMJpeakP (r = 0.709, P = 0.01) and T-Test (r = 0.589, P = 0.02). No significant between-group differences were observed for sprint tests or 30-15 IFT, including heart rate and estimated VO2max. Between groups, the percentage decrement (%Dec) in RSA-COD was significantly lower in MEL-G than NMEL-G (P = 0.05), although no significant difference was noted between RSA and RSA-COD. Within groups, no significant difference was observed between %Dec in RSA or RSA-COD; P = 0.697. This study presents specific anthropometric (significantly lower height) and physiological (significantly greater agility) reference values in Melanesians, which, taken together, might help coaches and physical fitness trainers to optimize elite futsal training and talent identification in Oceania.

Effect of different recovery durations between bouts in 3-a-side games on youth soccer players' physiological responses and technical activities.

AIM: The aim of this study was to investigate the effects of the length of recovery durations between bouts in 4x4min 3-a-side small-sided games (SSG) on time-motion analysis, technical actions and physiological responses of players. METHODS: Twelve young soccer players participated in 4 different 3-a-side games in which the recovery durations between bouts were different (R1: 1 min, R2: 2 min, R3: 3 min, and R4: 4 min). Heart rate (HR), total distance covered in different speed zones, and technical performance were monitored during all SSGs, whereas the rating of perceived exertion (RPE, CR-10) and venous blood lactate were determined at the end of the last bout of each SSG. RESULTS: Results showed that SSGs-R1 induced higher %HRreserve and lower successful passes (vs. R3 and R4 conditions, P<0.05), lower total passes (vs. R4 conditions, P<0.05), and greater distance covered in walking zone (0-6.9 km.h⁻¹) (vs. other 3 conditions, P<0.05). In addition, during the SSG-R3 players covered greater distances in high-intensity running zone (>18 km.h-1), performed more tackles (vs. R1 condition, P<0.05) and had more ball contacts (vs. R1 and R2 conditions, P<0.05). CONCLUSION: According to these results, it is thought that R1 and R2 are suitable for inducing higher physiological responses, while R3 and R4 are more appropriate for training aim to improve technical skills in 4x4min 3-a-side SSGs among young soccer players. These findings provide evidence for coaches to justify the selection of recovery duration between bouts in 3-a-side SSGs among young soccer players.

The application of the Yo-Yo intermittent endurance level 2 test to elite female soccer populations.

The aim of this study was to evaluate the application of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2) to elite female soccer populations. Elite senior (n = 92), youth (n = 42), domestic (n = 46) and sub-elite female soccer players (n = 19) carried out the Yo-Yo IE2 test on numerous occasions across the season. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance in domestic female players was 4.5%. Elite senior female players' Yo-Yo IE2 test performances were better (P < 0.01) than elite youth, domestic and sub-elite players (mean ± standard deviation; 1774 ± 532 vs 1490 ± 447, 1261 ± 449, and 994 ± 373 m). For elite senior female players, wide midfielders (2057 ± 550 m) had a higher Yo-Yo IE2 test performance (P < 0.05) than central defenders (1588 ± 534 m) and attackers (1516 ± 401 m), but not central midfielders (1764 ± 473 m) or full-backs (1964 ± 522 m). Large correlations were observed between Yo-Yo IE2 test performance and the total and high-intensity distance covered (r = 0.55; P < 0.05) during elite senior soccer matches (r = 0.70; P < 0.01). A large correlation was also obtained between Yo-Yo IE2 test performance and (r = 0.68; P < 0.01). Performances in the Yo-Yo IE2 test were greater (P < 0.05) in the middle and the end of the season compared with the preparation period for elite youth female players (1767 ± 539 and 1742 ± 503 vs 1564 ± 504 m) and in elite senior female players, Yo-Yo IE2 test performance increased by 14% (P < 0.01) after completing 4 weeks of intense training prior to the FIFA Women's World Cup Finals (2049 ± 283 vs 1803 ± 342 m). The data demonstrate that the Yo-Yo IE2 test is reproducible and is an indicator of the match-specific physical capacity of female soccer players. Furthermore, the Yo-Yo IE2 test illustrates sensitivity by differentiating intermittent exercise performance of female players in various competitive levels, stages of the season and playing positions.

Physical and technical comparisons between various-sided games within professional soccer.

This study compared the technical activity and physical movements of various-sided games within professional soccer. It also examined the test-retest reliability of sided games using various numbers of players. 10 elite male players from a Scottish Premier League performed small- (SSGs: 4 vs. 4), medium- (MSGs: 5 vs. 5 to 8 vs. 8) and large- (LSGs: 9 vs. 9 to 11 vs. 11) sided games each lasting for 3×5 min. Results show significant physical differences (p<0.05) between SSGs, MSGs and LSGs for most of the variables measured. It was shown that SSGs induce a significantly faster playing speed when compared to MSGs and LSGs (150.5 vs. 108.3 vs. 120.4 m.min-1, p<0.01) but significantly less (p<0.01) repeated high-intensity efforts (0.88 vs. 4.40 m), high-intensity running (7 vs. 39 m) and sprint distance (0 vs. 11 m) when compared to LSGs. Findings also revealed significant differences (p<0.05) between SSGs, MSGs and LSGs in technical demands (passes, dribbles, shots, headers). High levels of reproducibility (ICC=0.99) were yielded when using the same-sided games, pitch sizes and possession rules. This study provided information on different-sided games to facilitate its use as part of a periodised weekly structure.

Comparison of ground reaction forces and contact times between 2 lateral plyometric exercises in professional soccer players.

There are no studies which have examined the differences in kinetics between lateral plyometric exercises and the selection of these exercises is largely based on the experience and observation of coaches. This study aimed to compare ground reaction forces (GRF) and contact times (GCT) between 2 lateral plyometric exercises: lateral alternative leg hopping (HOP), and speed lateral footwork (SPEED). 16 professional male soccer players (age: 24.6±5.5 years; and BMI: 21.7±2.2 kg.m - 2) participated in this within-participant repeated measures study. 3-dimensional GRF data were measured by force platform. Our study revealed significant differences between the 2 lateral plyometric exercises in all kinetics parameters (F=573.7, P<0.01). HOP produced significantly longer GCT (0.45 s vs. 0.23 s, P<0.01, large effect), significantly higher values (P<0.05, large effect) in peak force (3.31 vs. 2.47 Body Weight [BW]), peak rate of force development (0.94 vs. 0.29 BW/s), and impulse (0.76 vs. 0.31 BW.s) except for peak force in the medial-lateral (P<0.05, medium effect) and impulse in the anterio-posterior direction (not significant, small effect). Therefore, SPEED is an exercise that aims to increase step frequency because of its short GCT (< 0.25 s) while HOP increases leg strength and power.

Variation of activity demands in small-sided soccer games.

The aim of the present study was to examine the physical and technical activity during different periods within small-sided soccer games (SSGs). 20 elite players completed 3 different SSGs (2-a-side, 3-a-side and 4-a-side games) in which the number of ball touches per individual possession was fixed at a maximum of 2. The duration and the pitch size of each SSG were strictly controlled (2 min, 3 min, 4 min, respectively; 1:75 m2) with each period repeated 4 times (P1, P2, P3, P4). The physical and technical activities, heart rate responses, blood lactate concentration and rating of perceived exertion (RPE) were analysed. The results showed a decrease of high and very high-intensity activities (from - 26.2% to - 37.7%, P<0.001), an increase of blood lactate concentration (from + 28.0% to + 76.9%), RPE (from + 29.0% to + 32.8%), and heart rate responses (~ 6.6%), and a significant alteration of technical activities from P1 to P4 in each SSG. The greatest differences from P1 and P4 were observed for the 2-a-side game when compared to the 3-a-side and 4-a-side games (P<0.05) for each variable analysed . In conclusion, the variation of the player's activity throughout the periods indicates that the duration and number of exercise periods used within SSGs is an important variable in determining the training stimulus in soccer-specific training.

Technical and physical demands of small vs. large sided games in relation to playing position in elite soccer.

The aim of this investigation was to compare the effects of common rule changes on technical and physical demands for elite soccer players in five playing positions during various 4-min small-sided games (SSGs) in comparison to 11-a-side matches. Forty international players classified into five positional roles participated in the study (25.3±2.4 years, 182.4±2.3 cm, 77.3±4.1 kg; M±SD). Players completed three different conditioned small-sided 4 vs. 4 games (1 ball touch=1T, 2 ball touches=2T and Free Play=FP) as well as two friendly matches. Heart rate (HR), blood lactate ([La]), ratings of perceived exertion (RPE) as well as physical and technical performance were analyzed. Compared to match-play, total distance covered per minute of play, high-intensity running activities (sprinting and high-intensity runs), total numbers of duels and lost ball possessions were significantly greater within SSGs for all playing positions (p<.05). In contrast, [La], percentage of successful passes and number of ball possessions were lower (p<.05) within SSGs, particularly with 1T and 2T rules, in comparison with match-play. HR was higher in SSGs compared to match-play for all playing positions, and RPE values were lower (p<.05) during the FP SSG for defensive midfielders, wide midfielders and forwards. In conclusion, this study revealed that 4 vs. 4 SSGs played with 1 or 2 ball touches increased the high-intensity running and the difficulty to perform technical actions, being more specific to match demands. Subsequently, it is of importance for coaches to understand the different physiological demands imposed upon players by varying the rules of SSGs and to understand the differences between positional roles.

Influence of the Numbers of Players in the Heart Rate Responses of Youth Soccer Players Within 2 vs. 2, 3 vs. 3 and 4 vs. 4 Small-sided Games.

The purpose of this study was to compare heart rate (HR) responses within and between small-sided games (SSG) training methods in elite young soccer players. Twenty-seven youth soccer players (age: 16.5 ± 0.5 years, height: 174.5 ± 5.5 cm, weight: 62.9 ± 8.3, velocity at maximal aerobic speed (MAS): 15.9 ± 0.9 km.h(-1)) performed 3 different SSG (2 vs. 2, 3 vs. 3, 4 vs. 4 without goalkeeper). In each SSG, HR was continuously measured and expressed as a mean percentage of HR reserve (%HRreserve). The mean %HRreserve calculated during the SSG was significantly lower during 4 vs. 4 (70.6 ± 5.9 %) compared to 2 vs. 2 (80.1 ± 3.6 %, p<0.001) and 3 vs. 3 (81.5 ± 4.3 %, p<0.001) SSG. Regardless of the time spent above 60, 65, 70, 75, 80, 85 and 90 % of HRreserve, 4 vs. 4 solicited lower percentage of time than 3 vs. 3 and 2 vs. 2. Intersubject coefficients of variation were significantly higher during 4 vs. 4 compared to 2 vs.2 and 3 vs. 3. The %HRreserve after 30s of recovery was significantly higher for 3 vs. 3 (70.6 ± 5.3 %) compared to 2 vs. 2 (65.2 ± 4.8 %, p<0.05) and 4 vs. 4 (61.6 ± 9.3 %, p<0.05). In conclusion, this study demonstrates that the physiological demands is higher during 2 vs. 2 and 3 vs. 3 compared to 4 vs. 4 in youth soccer players. This difference could be due to that young soccer players do not have the same technical ability and experience as adult players and thus, their activity during the 2 vs. 2 and 3 vs. 3 induces a greater physical demand due to their lack of experience. The age of the players could be linked with the physical demands within small-sided games.