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Original Research

Effects of the Number of Players and Game Type Constraints on Heart Rate, Rating of Perceived Exertion, and Technical Actions of Small-Sided Soccer Games

Abrantes, Catarina I.; Nunes, Marta I.; MaÇãs, Victor M.; Leite, Nuno M.; Sampaio, Jaime E.

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Journal of Strength and Conditioning Research: April 2012 - Volume 26 - Issue 4 - p 976-981
doi: 10.1519/JSC.0b013e31822dd398
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Abstract

Introduction

Despite the worldwide popularity of Soccer, there are still many uncertainties concerning the game's multidimensional requirements and consequently uncertainties when planning for teams' optimal training and conditioning processes. Game complexity can be addressed in practices by using specific drills that aim to reduce interactions and allow to increase players' participation in decision-making processes but, at the same time, preserve basic game variability (2,5,11,18,25). These drills are known as small-sided games (SSGs), and they are frequently used by coaches during training sessions because the training requirements can be closely matched to the competitive demands of the match play and also because they allow for a significant time economy because of the specificity of the training stimulus. Indeed, one of the major advantages of these training drills is the possibility of simultaneously eliciting technical, tactical, and physical determinants, which allow players to experience situations similar to those encountered in competitions (6,17). Also, they allow for practicing several team movement patterns, while maintaining competitive goals in which players should perform under stress and fatigue (11).

Research on SSGs was summarized recently (16), and several studies have analyzed the effects of changing task constraints, such as the playing area, the number of players, or even game rules (3,5,6,8,10,13–15,17,18) in variables such as heart rate (HR), lactate concentrations, and rating of perceived exertion (RPE). The usefulness of monitoring HR to regulate the intensity of training drills (17) and to provide information about the external and internal training loads is well documented (5). It has been reported that soccer SSGs can elicit HR responses around 90–95% of HRmax and can be used as an important physical conditioning drill (19). More recently, research was performed identifying similar time-motion characteristics of SSGs and competition in training sessions and match play (11). Altogether, these facts suggest that long-term exposure to such intensities leads to improvements in physical match performance (12) similar to that in more traditional methods of interval training (20).

Different task constraints seem to influence the SSG intensity. For example, several studies reported that increasing the number of players on the field reduces average HR responses (17). Conversely, this same situation seems to decrease the number of technical actions per player and consequently promote a reduction in training intensity (24). Available research suggests that SSGs should be monitored through a combination of HR and RPE to improve reliability (5). Results on this variable show that increasing the number of players, without changing the field dimensions, may contribute to reduce players' RPE (17).

There is also an interest in identifying the frequency and the effectiveness of technical actions (9,14,21–23) in each SSG format and situation. Results on this topic showed that SSG formats with fewer players allow increasing the frequencies of technical variables (22), as a result of having fewer options in the decision-making processes, that is, when playing 3 × 3, there are only 2 passing possibilities, whereas when playing 5 × 5 there are 4 passing possibilities. However, it is unknown if these differences in frequency of actions result in less effectiveness.

A frequent task constraint used by coaches when practicing soccer recurring to SSG formats is the usage of only offensive and only defensive teams. This game type constraints' purpose is to increase the frequency of specific behaviors, particularly those related to team coordination movements as related to major principles of play, while allowing to reduce complexity (29). There is no available research describing any effects of this game type task constraint, which would be helpful to coaches planning and practice process. Therefore, recognizing that each change in task constraints may influence exercise intensity, the purpose of this study was to compare the effects of the number of players (3 × 3 and 4 × 4) and game type (only offense situation OFF, only defense situation DEF and both situations GAME) on HR, RPE, and technical actions.

Methods

Experimental Approach to the Problem

The effects of game type constraints and their interaction with the number of players on physiological, perceptual, and technical variables are not well understood. To test the hypothesis, both the player number and the game type were manipulated in an attempt to alter the intensity of the SSG. Three different game type constraints (only offense situation OFF, only defense situation DEF, and both situations GAME) that are commonly used by soccer coaches were applied in 2 SSG formats (3 × 3, 4 × 4). We hypothesized that the number of players (3 or 4 per team) and game type constraint would offer different training stimulus to simulate the movement patterns of soccer competition. Before the SSG data gathering sessions, the coaches divided the players into 4 teams taking into account maximum equilibrium between teams' performances, and these sessions were completed in a random order. The first and second sessions began with a 3 × 3 SSG with goalkeepers, each team only in DEF or OFF, immediately followed by another 3 × 3 SSG with another group of 6 players. In the third session, the GAME situations were carried for the 3 × 3 SSG using the same groups of players. This protocol was repeated for the 4 × 4 SSG.

Subjects

The sample included 16 young male soccer players (age 15.75 ± 0.45 years, height 172.4 ± 4.83 cm, body mass 64.5 ± 6.44, HRmax199.1 ± 9.08 b·min−1, and 8.06 ± 1.98 years of practice). All the players were recruited from the same high-level team and tested 1 week after the end of the competitive season (in the beginning of June). All the players were requested to refrain from strenuous exercise for 24 hours before the field-testing sessions. Written informed consent was received from all the participants and parents after they were given a detailed explanation about the aims, benefits, and risks involved in this investigation. The participants were told that they were free to withdraw from the study at any time without penalty. The study was approved by the Ethics Committee of the Research Center for Sports Sciences, Health and Human Development, Vila Real, Portugal, and the local ethics committee before the commencement of the assessments. The study protocol followed the guidelines laid down by the Declaration of Helsinki.

Procedures

The subjects arrived at the field 30 minutes earlier and were informed about the major protocol details but not about the objective of the study. They then performed the usual 15 minutes of standardized warm-up that includes running at low intensities and dynamic stretching exercises. The HR monitors were placed before the start of each session.

Previous to testing, all the participants performed the Yo-yo Intermittent Endurance Test (level 2) according to previously described procedures (4–7) to determine individual maximal HR and later determine HR intensity zones during the SSG: zone 1 (<75% HRmax); zone 2 (75–84.9% HRmax); zone 3 (85–89.9% HRmax), and zone 4 (≥90% HRmax) (18). The HR was continuously monitored with 5-second average intervals using Polar Team System (Polar, Kempele, Finland). The reliability of HRmax has been previously reported (17), with TE% being <5%. All the games were held in natural grass fields with 20 m × 30 m for 3 × 3 and 20 m × 40 m for the 4 × 4 (100-m2 ratio per player) marked with normal landmarks. Each game lasted for 24 minutes in an interval training format, consisting of 4 sets of 4 minutes duration, interspersed by 2 minutes of active recovery by low-intensity running (22). After each SSG, each subject was asked to manually register his RPE value. The Borg scale (6–20) was printed on paper and used to help the players make a decision (5). The reliability of RPE has been previously reported (17), with the typical error expressed as a percentage of the mean (TE%) being 1–2 units. Several balls were placed around the playing area to be immediately replaced when necessary, avoiding interruptions in exercise (6,7,17,22).

During the game, each team coach was allowed only to encourage the subjects verbally. As usual in regular practices sessions, the players were allowed to have isotonic drinks ad libitum during the recovery period (22). All the sessions were at the same time of the day (6 PM) to avoid HR circadian rhythm variation. To enable game notational analysis, a video camera was placed 106 cm above the ground, positioned toward the line midfield in every game and covering the entire playing area. The footage made during the course of the games was used to perform the notational analysis of technical actions by 2 expert observers. The variables analyzed were the following: Pass, Receive, Dribble, Shot, Tackle, and Interception (22,24). All these variables were expressed in percentage of efficacy. Intrarater and interrater reliabilities were high for all the variables (lower values of Cohen K > 0.91 and 0.90, respectively).

Statistical Analyses

Data are expressed as means (±SD). The RPE and technical variables were analyzed with a 2 × 3 repeated measures analysis of variance (ANOVA): number of players (3 × 3 or 4 × 4) and task constraint (OFF, DEF, or GAME). To analyze HR data, the zone repeated factor (with 4 levels) was included in the model, resulting in a 2 × 3 × 4factorial ANOVA, with all assumptions to these models accounted (28). Effect sizes were used to access pairwise differences and interpreted based on the following criteria: <0.20 = trivial, 0.20–0.59 = small, 0.60–1.19 = moderate, 1.20–2.0 = large, >2.0 = very large (4). Only the significant interactions were described (27). All statistical analyses were performed using Statistica software version 8 (Statsoft, Tulsa, OK, USA), and the significance level was set at p ≤ 0.05.

Results

The results from simple effects and interactions between the number of players and game type constraints in time spent in each of the 4 HR zones and in RPE are given in Table 1. Perceived exertion was significantly higher when playing 3 × 3 in comparison with 4 × 4 (Table 1). Concerning the task constraint, the higher values of RPE were obtained in GAME, and there were significant differences between OFF and the other 2 game type constraints (F = 4.5, p = 0.023, ESGAMEvs. OFF = 2.14; ESGAME vs. DEF = 2.36). The interaction between game type constraints and the number of players revealed very similar values in 3 × 3 and different values in 4 × 4, with higher RPE in GAME and lower in OFF (Table 1).

Table 1
Table 1:
Results from simple effects and interactions between the number of players and game type constraints in RPE and time spent in each of the 4 HR zones.*

Significant interactions were found between HR zones and the number of players (F = 4.3, p = 0.011) and also between HR zones and game type constraints (F = 5.4, p < 0.001). First, the results suggest that 4 × 4 game type constraints are related to spending more time under 85% of the HRmax, whereas the 3 × 3 game type constraints seem to elicit an important amount of time spent >90% of the HRmax. Concerning game type constraints, results suggest that the DEF situation elicited less time in HR zone 4 (Table 1). The triple interaction between the number of players, situation, and HR zones was not significant (F = 1.5, p = 0.206).

Results from simple effects and interactions between the number of players and game type constraints in technical action are given in Table 2. No differences were found in the effectiveness of these variables in any situation, exception made to the interaction in passes (F = 5.5, p = 0.038) identifying higher pass effectiveness in the 4 × 4 GAME and lower effectiveness in the 3 × 3 GAME (Table 2).

Table 2
Table 2:
Results from simple effects and interaction between the number of players and game type constraints in technical actions.*

Discussion

The purpose of this study was to compare the effects from the number of players (3 × 3 and 4 × 4) and different game type constraints (when only playing offense, only playing defense, and both situations) on HR, RPE, and technical actions of soccer SSGs. Generally, our results showed that the time spent in each HR intensity zone was affected by the number of players, showing more time spent in zone 2 (75–84.9%) in both 3 × 3 and 4 × 4. However, in the 4 × 4 SSG, there was substantial additional time in zone 1 (<75%), whereas in 3 × 3, there was more time in zone 4 (>90%). Available research has shown that when playing 3 × 3, the HR is generally similar to 11 × 11, and the 4 × 4 format usually results in lower HR average values (24). Indeed, in SSGs with fewer players, the higher individual ball possession time has been associated with higher exercise intensities (1,25) and also with higher energy expenditure (26).

When game type constraints were analyzed, the OFF and GAME elicited more time in HR zones 2 and 4, and DEF elicited more time in zones 2 and 1. In fact, in the DEF situation, the players do not have ball possession, and this may be one of the factors associated with a higher intensity in SSGs (1,25). On the other hand, it may be suggested that the motivation to practice defensive situations continuously can be lower when comparing with offensive or normal game situations. To prevent this possibility, the players were continuously encouraged by coaches and researchers to maintain an intense game pace, thereby preventing them from decreasing the intensity of play. However, it is always difficult to verify if less intensity in DEF situations was caused by the nature of the task, by a reduced motivation status, or a combination of both.

The analysis of HR data in the time spent in each intensity zone provides additional information for the SSG training format. The 3 × 3 OFF and GAME exhibited similar values in each HR training zone (mostly in zones 4 and 2), whereas when playing 4 × 4, the time distributions were wider (zone 2 followed by zone 4 in GAME and zone 2 followed by zone 3 in OFF). These results may suggest that playing 3 × 3 in any of the studied game type constraints is substantially more intense than playing 4 × 4 in which the differences between OFF, DEF, and GAME are much narrower. If the training session aims to improve aerobic performances, generally the 3 × GAME and OFF seems more useful than any 4 × 4 situation. Accordingly, it seems that DEF situations could be used as a recovery drill, while simultaneously allowing the practice of team defensive coordination.

Available research has already identified higher RPE values in reduced SSG formats (17,25). In this study, the 3 × 3 SSG format also elicited the higher RPE response. Reducing the number of players increases the perceived exertion, and this was also seen in more time spent in higher intensity training zones. This fact may be explained by the greater need of players to be moving to create several passing opportunities, because the reduction in the number of players on the field reduces the number of possible solutions and lowers team ball possession but increases the interaction of each player with the ball or opponents (24). In the effect of situation, playing only offense or only defense has decreased the RPE. For an almost identical RPE (15.9 ± 0.5 and 16.0 ± 0.3, respectively, OFF and DEF), the OFF situations elicited higher time in HR zones 3 and 4, whereas DEF elicited more time in zone 2. It may be suggested that other combined factors could affect the RPE response, such as the reduced interaction with the ball in DEF and constant ball possession in OFF.

The introduction of the fourth player implies substantial differences between both situations, with OFF being perceived as less intense, despite the fact of having more time in HR zones 3 and 4. When playing GAME situation, there is a constant need to create offensive and defensive solutions, causing a higher RPE response, probably associated with an increased intensity of play. In fact, it seems likely that the players in DEF or OFF have less strategic concerns because of the lack of transition phases in these situations, and therefore, this would be decreasing the intensity of play. In fact, these transition phases are considered as key factors to success in soccer, and therefore, it should be of no surprise that its presence (in GAME) causes effects in all variables.

Available research has identified increases in frequency of technical actions in SSGs with fewer players (24). However, our results do not allow identifying differences in the effectiveness of these variables. Thus, when playing 3 × 3, it is expected that players perform more passes or dribbles; however, their effectiveness in 3 × 3 or 4 × 4 is the same. This same trend was identified for all the technical actions studied. The interaction between game type constraints and the number of players in passes seems very important when choosing the most adequate SSG format. In fact, in 4 × 4 situations, there is an extra passing line, and this seems to attenuate the psychophysiological stress of players at the time of the skill acquisition process. Additionally, playing OFF in 4 × 4 decreased passing performance, probably as the effect of being always in the same situation, leading to increase predictable behaviors and physical fatigue.

Practical Applications

Despite the extensive use of SSGs in soccer practices, the understanding of their impact in physical, technical, and tactical skills is still limited. This study is the first to report differences in game type constraints such as GAME, OFF, and DEF and their interactions with the number of players in SSG. The use of these game type constraints (GAME, OFF, and DEF) when playing 3 × 3 or 4 × 4 SSGs should be carefully planned. The 3 × 3 situations seem more adequate to optimize aerobic performances; however, the DEF situations seem less intense and should be only used to promote aerobic recovery effects. The inclusion of an additional player had completely different interactions, and only GAME situation presented adequate intensity. Although the utility of OFF and DEF in 4 × 4 when practicing team coordination is unquestionable, these situations seem to promote important intensity decreases.

Another very important result was that although 3 × 3 SSGs present higher frequencies of technical actions, there were no differences in effectiveness. Results from passing should be carefully examined because they might suggest that more variability in environmental conditions and less psychophysiological stress could lead to better efficacy in this key action.

References

1. Balsom PD, Wood K, Olsson P, Ekblom B. Carbohydrate intake and multiple sprint sports: With special reference to football (soccer). Int J Sports Med 20: 48–52, 1999.
2. Capranica L, Tessitore A, Guidetti L, Figura F. Heart rate and match analysis in pre-pubescent soccer players. J Sport Sci 19: 379–384, 2001.
3. Casamichana D, Castellano J. Time-motion, heart rate, perceptual and motor behaviour demands in small-sides soccer games: Effects of pitch size. J Sport Sci 28: 1615–1623, 2010.
4. Cohen J. Statistical Power Analysis for Behavioral Sciences. Academic Press, New York, 1977.
5. Coutts AJ, Rampinini E, Marcora SM, Castagna C, Impellizzeri FM. Heart rate and blood lactate correlates of perceived exertion during small-sided soccer games. J Sci Med Sport 12: 79–84, 2009.
6. Dellal A, Chamari K, Pintus A, Girard O, Cotte T, Keller D. Heart rate responses during small-sided games and short intermittent running training in elite soccer players: A comparative study. J Strength Cond Res 22: 1449–1457, 2008.
7. Dellal A, Wong D, Moalla W, Chamari K. Physical and technical activity of soccer players in the French First League—With special reference to their playing position. Int Sportmed J 11: 278–290, 2010.
8. Duarte R, Batalha N, Folgado H, Sampaio J. Effects of exercise duration and number of players in heart rate responses and technical skills during futsal small-sided games. Open Sports Sci J 2: 37–41, 2009.
9. Gabbett T, Jenkins D, Abernethy B. Game-based training for improving skill and physical fitness in team sport athletes. Int J Sports Sci Coach 4: 273–283, 2009.
10. Gabbett TJ, Jenkins DG, Abernethy B. Physiological and skill demands of ‘on-side’ and ‘off-side’ games. J Strength Cond Res 24: 2979–2983, 2010.
11. Gabbett TJ, Mulvey MJ. Time-motion analysis of small-sided training games and competition in elite women soccer players. J Strength Cond Res 22: 543–552, 2008.
12. Helgerud J, Engen LC, Wisloff U, Hoff J. Aerobic endurance training improves soccer performance. Med Sci Sport Exerc 33: 1925–1931, 2001.
13. Hill-Haas S, Rowsell G, Coutts A, Dawson B. The reproducibility of physiological responses and performance profiles of youth soccer players in small-sided games. Int J Sport Physiol 3: 393–396, 2008.
14. Hill-Haas SV, Coutts AJ, Dawson BT, Rowsell GJ. Time-motion characteristics and physiological responses of small-sided games in elite youth players: The influence of player number and rule changes. J Strength Cond Res 24: 2149–2156, 2010.
15. Hill-Haas SV, Coutts AJ, Rowsell GJ, Dawson BT. Generic versus small-sided game training in soccer. Int J Sports Med 30: 636–642, 2009.
16. Hill-Haas SV, Dawson B, Impellizzeri FM, Coutts AJ. Physiology of small-sided games training in football. A systematic review. Sports Med 41: 199–220, 2011.
17. Hill-Haas SV, Dawson BT, Coutts AJ, Rowsell GJ. Physiological responses and time-motion characteristics of various small-sided soccer games in youth players. J Sport Sci 27: 1–8, 2009.
18. Hill-Haas SV, Rowsell GJ, Dawson BT, Coutts AJ. Acute physiological responses and time-motion characteristics of two small-sided training regimes in youth soccer players. J Strength Cond Res 23: 111–115, 2009.
19. Hoff J, Wisloff U, Engen LC, Kemi OJ, Helgerud J. Soccer specific aerobic endurance training. Br J Sport Med 36: 218–221, 2002.
20. Impellizzeri FM, Marcora SM, Castagna C, Reilly T, Sassi A, Iaia FM, Rampinini E. Physiological and performance effects of generic versus specific aerobic training in soccer players. Int J Sports Med 27: 483–492, 2006.
21. Katis A, Kellis E. Effects of small-sided games on physical conditioning and performance in young soccer players J Sports Sci Med 8: 374–380, 2009.
22. Kelly DA, Drust B. The effect of pitch dimensions on heart rate responses and technical demands of small-sided soccer games in elite players. J Sci Med Sport 12: 475–479, 2009.
23. Mallo J, Navarro E. Physical load imposed on soccer players during small-sided training games. J Sports Med Phys Fitness 48: 166–171, 2008.
24. Owen A. Small-sided games: The physiological and technical effect of altering pitch size and player numbers. Insight: F A Coaches Assoc 7:50–53, 2004.
25. Rampinini E, Impellizzeri FM, Castagna C, Abt G, Chamari K, Sassi A, Marcora SM. Factors influencing physiological responses to small-sided soccer games. J Sport Sci 25: 659–666, 2007.
26. Reilly T, Ball D. The net physiological cost of dribbling a soccer ball. Res Q Exerc Sport 55: 267–271, 1984.
27. Thomas J, Nelson J, Silverman S. Research Methods in Physical Activity. Champaign, ILHuman Kinetics2005
28. Vincent W. Statistics in Kinesiology. Champaign, IL: Human Kinetics, 2005.
29. Wade A. Principles of Team Play. Spring City, PA: Reedswain Inc., 1996.
Keywords:

offense; defense; notational analysis; performance; youth players

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