Impact of the number of players on the emergence of creative movements in small-sided soccer games: a systematic review emphasizing deliberate practice.

Introduction: Creativity is a recognized quality in various areas, including sports. Within the training processes, various modifications to objectives, game configurations, rules, among other factors, can be considered to favor creative solutions to the tactical problems inherent to soccer. This systematic review aimed to identify the impact of the number of players on the emergence of creative movements in small-sided soccer games, emphasizing deliberate practice. Methods: A systematic review of Scopus, PubMed, Scielo, PsycInfo, SportDiscus and Lilacs databases was performed according to PRISMA guidelines. Eligibility criteria were defined based on the elements of population, context and concept. Only full articles published in scientific journals written in English were included. No period restriction was applied. Results: Five papers were included and the results of studies indicate greater number of actions, variability, and creativity in small-sided games compared to formal soccer matches. When comparing different small-sided game formats, 5 v 5 showed higher values in terms of total number of actions compared to 7 v 7, and the absolute number of original and creative actions tended to decrease as the game format increased. Imbalanced small-sided games format can promote increased exploratory behavior. Structural manipulation in goal positioning in 5 v 5 games may also influence the originality of tactical behaviors, while the use of different ball types in 4 v 4 games appears to decrease fluency values. In 6 v 6 games, fluency and versatility are negatively impacted. Conclusion: Reduced game formats with fewer players and in smaller field dimensions provide more suggestive environment for exploratory behavior, variability and original and creative actions. The protocol was registered on the Open Science Framework (OSF) on 2 December 2022 (DOI: 10.17605/OSF.IO/VN6YZ). Systematic review registration: [https://osf.io/jmf4k/].

High-Intensity Intermittent Exercise Performed on the Sand Induces Higher Internal Load Demands in Soccer Players.

This study aimed to examine the acute physiological effect of shuttle-run-based high-intensity intermittent exercise (HIIE) performed at the same relative speed (i. e., 100% PST-CAR) on sand (SAND) and grass (GRASS) in male junior soccer players. Seven Under-23 Brazilian national league ("Série A") soccer players completed four testing sessions in either SAND or GRASS surface condition. The first two testing sessions consisted of performing a maximal progressive shuttle-run field protocol until volitional exhaustion (Carminatti's test, T-CAR), whereas the third and fourth sessions comprised a HIIE session on each ground surface. The HIIE session consisted of three 5-min bouts [12 s shuttle-run (with a direction change every 6 s)/12 s of passive rest] performed at 100% of T-CAR peak speed (PST-CAR) with 3 min of passive recovery between sets. Measurements of oxygen uptake (VO2), heart rate (HR), blood lactate concentration ([La]), and rating of perceived exertion (RPE) were performed during all conditions. The SAND condition elicited significantly higher %VO2peak (94.58 ± 2.73 vs. 87.45 ± 3.31%, p < 0.001, d = 2.35), %HRpeak (93.89 ± 2.63 vs. 90.31 ± 2.87%, p < 0.001, d = 1.30), RPE (8.00 ± 0.91 vs. 4.95 ± 1.23 a.u., p < 0.001, d = 2.82), and [La] (10.76 ± 2.37 vs. 5.48 ± 1.13 mmol/L, p < 0.010, d = 2.84). This study showed that higher internal workloads are experienced by the players during a single HIIE session performed on a softer surface as SAND, even when the exercise intensity was individualized based on 100%PST-CAR.

Predicting Maximal Lactate Steady State from Carminatti's Shuttle Run Test in Soccer Players.

The objective of the present study was to determine the validity of Carminatti's shuttle run incremental test-T-Car derived parameters in estimating the maximal lactate steady state determined in shuttle run format. Eighteen soccer players performed a T-Car test, and several trials to determine the maximal lactate steady state. From T-Car were derived the heart rate deflection point, peak speed, maximal heart rate and parameters resulting from percentage of peak measures. The validity was accessed by Bland-Altman plots, linear regressions, and two one-sided tests of equivalence analysis. The results showed the speed at 80.4% of T-Car peak speed, the heart rate deflection point and the 91.4% of maximal heart rate were equivalent to maximal lactate steady state (Mean difference; ±90% compatibility interval; -0.8; ±1.5%, -0.4; ±1.1%, and 0.0; ±2.7%, respectively). Additionally, peak speed during the T-Car test was a stronger predictor of maximal lactate steady state (MLSS [km/h]=2.57+0.65 × sPeak; r=0.82 [90% CI; 0.62-0.92], standard error of the estimate=3.6%; 90% CI ×/÷1.4). Therefore, soccer players can use the T-Car derived parameters as a noninvasive and practical alternative to estimate the specific maximal lactate steady state for soccer.

Training Loads and RSA and Aerobic Performance Changes During the Preseason in Youth Soccer Squads.

The aims of this study were to compare the internal training load (ITL) in soccer players of two competitive age groups (under-15 [U-15] and under-19 [U-19]) during an 8-week preseason training period and compare the associated changes in physical performance measures. Eighteen U-15 and twelve U-19 players were monitored over an 8-week period during the preseason phase. The ITL was monitored using the session rating of perceived exertion (RPE) method. Before and after the preseason period, physical performance was assessed by best (RSAbest) and mean (RSAmean) times in a repeated sprint ability (RSA) test and peak velocity derived from the Carminatti test (PVT-CAR). Total weekly ITL increased with age (U-15: 13770 ± 874 AU vs. U-19: 33584 ± 2506 AU; p < 0.001). In addition, U-19 players perceived training sessions as heavier than U-15 players (6.1 ± 0.3 vs. 5.3 ± 0.3 AU, respectively; p < 0.001). After the preseason period, very likely to almost certainly positive changes were observed for all performance measures in both age groups. However, the U-15 group had possibly superior gains in RSAbest (+1.40%, 90%CL -0.29 to 3.05, with ES = 0.35) and likely higher effects in RSAmean (+1.89%, 90%CL 0.04 to 3.70, with ES = 0.53) and PVT-CAR (+2.71%, 90%CL 0.35 to 5.01, with ES = 0.37) compared to the U-19 group. In conclusion, our findings demonstrate that the U-19 group accumulate higher total weekly ITLs than the U-15 group during the preseason phase due to longer and heavier training sessions. However, the U-15 group obtained superior gains in soccer-specific physical abilities while accumulating half the total ITLs during lighter training sessions.

Physiological Responses During the Time Limit at 100% of the Peak Velocity in the Carminatti's Test in Futsal Players.

The aim of this study was to investigate the physiological responses during the time limit at the intensity of the peak velocity of the Carminatti's test (T-CAR). Ten professional futsal players (age, 27.4 ± 5.8 years, body mass, 78.8 ± 8.5 kg, body height, 175.8 ± 6.8 cm, body fat mass, 14.1 ± 2.6%) took part in the study. The players performed three tests, with an interval of at least 48 hours, as follows: the T-CAR to determine the peak velocity and the maximal heart rate; an incremental treadmill protocol to determine the maximal physiological responses; and a time limit running test at the peak velocity reached in the T-CAR. During the last two tests, a portable gas analyzer was used for direct measurement of cardiorespiratory variables. It was shown that the peak velocity was not significantly different from the maximal aerobic speed achieved in the laboratory (p = 0.213). All athletes reached their maximum oxygen uptake during the time limit test. The maximum oxygen uptake achieved during the time limit test was not different from that observed in the laboratory condition (51.1 ± 4.7 vs. 49.6 ± 4.7 ml·kg-1·min-1, respectively, p = 0.100). In addition, Bland and Altman plots evidenced acceptable agreement between them. On average, athletes took ~140 s to achieve maximum oxygen uptake and maintained it for ~180 s. Therefore, the peak velocity intensity can be used as an indicator of maximal aerobic power of futsal athletes and the time limit can be used as a reference for training prescription.

The effect of two generic aerobic interval training methods on laboratory and field test performance in soccer players.

The purpose of this study was to compare the effects of 2 generic aerobic training models, based on peak running velocity in Carminatti's test (PVT-CAR) in U-20 elite soccer players. Seventeen soccer players (age: 17.9 ± 1.0 years; 178.6 ± 5.0 cm; 73.6 ± 6.6 kg; 11.1 ± 1.3%) from a team competing in a national junior league took part in the study. The athletes performed a series of pre- and posttraining tests (incremental test on a treadmill to determine the maximal oxygen uptake [(Equation is included in full-text article.)], velocity at maximal oxygen uptake [(Equation is included in full-text article.)], the lactate threshold [LT], and T-CAR). The interval training models applied were with 180° direction change (T12:12; n = 9) and without direction change (T6:6; n = 8). No significant interaction (time vs. group) was observed for the majority of variables analyzed (p > 0.05), although significant main effects in time were evident regarding peak treadmill velocity (PVTREAD) (F = 56.3, p < 0.0001), (Equation is included in full-text article.)(F = 35.8, p < 0.0001), LT (F = 57.7, p < 0.0001), and PVT-CAR (F = 52.9, p < 0.0001). Moreover, there was no significant change in (Equation is included in full-text article.)between pre and posttraining period (F = 4.26, p = 0.056) in both training groups. Thus, it can be concluded that the prescribed training with and without direction change in the intensity of the PVT-CAR increases the PVTREAD, the (Equation is included in full-text article.), the LT, and the PVT-CAR similarly.

Validity of Carminatti's test to determine physiological indices of aerobic power and capacity in soccer and futsal players.

The aim of this study was to verify the validity of a new progressive distance and fixed time test (Carminatti's test [TCAR]) in estimating the main physiological indices of aerobic fitness in team-sport players. Thirty professional national level team-sport players (n = 12 futsal players and 18 soccer players) volunteered to participate in this study. The subjects performed the TCAR and a laboratory incremental treadmill test (ITT). The TCAR required subjects to complete repeated sets of 5 × 12-second shuttle-running bouts at progressive speed until volitional exhaustion. Each 12-second bout and series were separated by a 6- and 90-second recovery periods, respectively. The initial distance was set at 15 m and was progressively increased by 1 m each set. The ITT commenced at a velocity of 9.0 km·h(-1) and was increased by 1.2 km·h(-1) each 3 minutes until volitional exhaustion. Peak TCAR running velocity resulted not significantly (p > 0.05) different from speed at VO2max (vVO2max) during ITT. Peak TCAR running velocity was significantly correlated (p < 0.01) with vVO2max (r = 0.55) and VO2max (r = 0.51). No significant differences were found (p > 0.05) among the mean values of velocity and heart rate at the anaerobic threshold, estimated in the TCAR test and measured in the ITT. In light of this study results, the TCAR can be considered as a viable field test to estimate aerobic power and capacity in team-sports players. The limited devices and space required by TCAR warrant consideration for those strength and conditioning professionals who deal with team sports.

Physiological demands of team-handball referees during games.

The objective of the present study was to examine the aerobic fitness and the physiological demands during competitive games in elite handball referees. Sixteen referees (age: 34.9 +/- 3.4 years, body mass: 77.4 +/- 10.6 kg, height: 173.5 +/- 7.5 cm, percent fat: 22.3 +/- 6.6%) of national and international levels (14 men and 2 women) were submitted to a multistage fitness test, to determine peak velocity (PV) and maximal heart rate (HR). After 48 hours, referees performed a submaximal intermittent shuttle-running test (3 minutes at 75 and 90% PV with 1-minute recovery), to determine speeds and HR at selected blood-lactate concentrations (2.0 and 4.0 mmol.L(-1)). Game intensities were arbitrarily established as follows: HR4mmol (severe). Eight referees (2 per game) were monitored in 4 national level games. The mean VO(2)max of the referees was 48.5 +/- 6.1 ml.kg(-1).min(-1). Maximal HR, HR2mmol, and HR4mmol were 193 +/- 10, 154 +/- 13, and 167 +/- 10 b.min, respectively. The percent time spent in the moderate intensity domain was predominant (moderate 96.4%, heavy 2.3%, and severe 1.3% of total time, p < 0.05). These findings indicate that handball refereeing is of moderate intensity. In light of this study, results aerobic fitness does not seem to be a limiting factor in handball refereeing.

Diferença entre intensidade do exercício prescritapor meio do teste TCAR no solo arenoso e na grama / Prescribed differences in exercise intensity based on the TCARtest over sandy ground and grass

The intensity of training might be influenced by exercise mode and type of terrain. Thus, the objective of this study was a) to compare the physiological indices determined in the TCAR test carried out on natural grass (NG) and sandy ground (SG), and b) to analyze heart rate (HR) and blood lactate responses during constant exercise on SG and NG. Ten soccer players (15.11 ± 1.1 years, 168 ± 4.0 cm, 60 ± 4.0 kg) were submitted to the TCAR test to determine peak velocity (PV) and the intensity corresponding to 80.4% PV (V80.4) on NG and SG. The second evaluation consisted of two constant load tests (CLT) (80.4% PV on NG and SG) with a duration of 27 min. The paired Student t-test was used to compare the tests carried out on NG and SG. ANOVA (two-way), complemented by the Tukey test, was used to compare lactate concentrations [La] at 9, 18 and 27 min between the two types of terrain. A p value <0.05 was adopted. PV and V80.4 (15.3±1.0 and 12.3±0.6 km/h) were significantly higher on grass than on sand (14.3±1.0 and 11.5±0.4 km/h). Lactate concentration during the CLT [LaV80.4] was significantly higher on sand (4.1±0.9 mmol/L) than on grass (2.8±0.7 mmol/L). In the CLT, no significant difference in mean HR was observed between the two terrains, whereas there was a difference in [La]. In conclusion, the type of terrain interferes with indicators associated with aerobic power and capacity obtained by the TCAR test.

The intensity of training might be influenced by exercise mode and type of terrain. Thus, the objective of this study was a) to compare the physiological indices determined in the TCAR test carried out on natural grass (NG) and sandy ground (SG), and b) to analyze heart rate (HR) and blood lactate responses during constant exercise on SG and NG. Ten soccer players (15.11 ± 1.1 years, 168 ± 4.0 cm, 60 ± 4.0 kg) were submitted to the TCAR test to determine peak velocity (PV) and the intensity corresponding to 80.4% PV (V80.4) on NG and SG. The second evaluation consisted of two constant load tests (CLT) (80.4% PV on NG and SG) with a duration of 27 min. The paired Student t-test was used to compare the tests carried out on NG and SG. ANOVA (two-way), complemented by the Tukey test, was used to compare lactate concentrations [La] at 9, 18 and 27 min between the two types of terrain. A p value <0.05 was adopted. PV and V80.4 (15.3±1.0 and 12.3±0.6 km/h) were significantly higher on grass than on sand (14.3±1.0 and 11.5±0.4 km/h). Lactate concentration during the CLT [LaV80.4] was significantly higher on sand (4.1±0.9 mmol/L) than on grass (2.8±0.7 mmol/L). In the CLT, no significant difference in mean HR was observed between the two terrains, whereas there was a difference in [La]. In conclusion, the type of terrain interferes with indicators associated with aerobic power and capacity obtained by the TCAR test.