Contemporary practices of Portuguese and Brazilian soccer coaches in designing and applying small-sided games

Study design

This study utilized a cross-sectional study design to investigate and describe the current practices of Portuguese and Brazilian soccer coaches concerning the design and implementation of SSGs in soccer. The a priori sample size calculation utilized an effect size threshold of 0.3, which corresponds to a small effect size. This choice was made due to the absence of similar studies that could provide a mean difference between populations as a reference point. Additionally, a p-value of 0.05 and a power of 0.95 were established for the analysis. In terms of degrees of freedom, since the majority of studies involved a dichotomous questions comparing two populations (Portuguese and Brazilian), a value of 2 was assigned. Utilizing these specified parameters in the G*power software (version 3.1) for a chisquared goodness-of-fit test (option of contingency tables), the recommended a priori sample size was determined to be 172.

A diverse group of coaches, including head coaches, assistant coaches, and physical trainers, were invited to participate in the survey and share their practices and perspectives regarding the utilization of SSGs in soccer training. The primary objective was to gain a comprehensive understanding of how SSGs are currently being designed and integrated into soccer training programs, aiming to identify prevailing trends and approaches employed by coaches in both Portugal and Brazil. The study adhered to ethical standards for research involving human subjects, in accordance with the principles outlined in the Declaration of Helsinki. Prior to participating in the survey, informed consent was obtained from all participants. It is important to note that participation was entirely voluntary, and coaches had the option to withdraw from the study at any point without facing any adverse consequences or penalties.

Setting

The online survey was administered using Google Forms and was available for participation from July 9, 2022, to July 18, 2022. The recruitment process for participants involved reaching out to coaches who expressed an interest in SSGs during a webinar held on July 9, 2022. Participants in this webinar were initially introduced to the fundamental concepts and significance of SSGs in a broad manner. This introductory session aimed to provide a comprehensive understanding of the terminologies and concepts associated with SSGs. Subsequently, the coaches received a detailed clarification regarding these games and their significance before proceeding with the survey. Additionally, the survey link was shared through the researchers’ networks, which included contacts in various soccer clubs and former students actively engaged in the sport.

To prioritize confidentiality and encourage candid responses, the survey was designed to be completely anonymous. This approach ensured that coaches could freely provide their feedback and insights in a secure and confidential manner, fostering an environment of openness and trust.

Participants

The survey successfully gathered responses from 187 participants, all from Portugal and Brazil, and there were no missing data points. The participant breakdown included 82 Portuguese men, and 105 Brazilian men. These coaches occupied various roles within the technical staff, with 63 individuals serving as head coaches, 38 as assistant coaches, 38 as physical trainers, and 48 in other capacities related to the technical staff, such as match analysts and physiologists. Furthermore, the participants encompassed both youth (n = 102) and adult competitive levels (n = 59), with some not currently affiliated with a specific team or coaching position.

Table 1 presents an insightful overview of the participants’ characteristics and backgrounds. It includes information on their academic qualifications, certificate levels in soccer, years of experience in soccer, and their current involvement in competitive levels of the sport. This data provides valuable context for understanding the perspectives and experiences of the participants in relation to SSGs.

Small-sided games survey

For this study, a comprehensive survey was developed to investigate the use and value of SSGs. The survey’s main domains, covering “when,” “how,” and “why” SSGs are used, were initially drafted by a team of three researchers, with questions based on existing literature.

To ensure the survey’s quality and validity, three independent academic experts in SSGs, recognized soccer researchers according to ExpertScape, were invited to review the draft. Their valuable feedback led to revisions and improvements in the wording and structure of the questions.

Next, the revised survey was sent to three additional experts, consisting of four soccer coaches with a minimum UEFA B license. Among them, two had no academic background in sports sciences, while the other two did. Their perspectives were considered to further enhance the survey’s content.

After incorporating feedback from both the academic experts and soccer coaches, the final version of the survey was sent back to the initial three academic experts for their final evaluation. Once their approval was obtained, the survey was presented as a supplementary file and launched online using Google Forms.

Participants were provided with a clear explanation of the survey’s purpose, research design, and assurances of anonymity, confidentiality, and data protection before proceeding. Their voluntary participation and consent were confirmed before they completed the questionnaire.

The survey encompassed a demographic questionnaire comprising 18 closed questions to gather data on the participants’ academic and professional backgrounds. In the “when” domain, 14 questions were presented to explore the frequency of Small-Sided Games (SSGs) implementation during the season, within a training week, and within individual training sessions. The “how” domain consisted of 43 questions aimed at identifying the primary objectives of using SSGs and how coaches select specific task constraints to align with these objectives. Lastly, the “why” domain featured 15 questions focused on understanding the perceived importance of utilizing SSGs for different training objectives. For the original version of the questionnaire, please refer to the supplementary file 1.

It is crucial to provide clarity regarding the terminology used in this survey. SSGs were broadly defined and explained to the participating coaches as drill-based games that maintain the dynamics of the actual game while incorporating task constraints and simplifying the format of the official game. However, it is worth noting that the more accurate term for these activities would be “conditioned games,” as it comprehensively describes their nature [1]. Nevertheless, due to the widespread use and popularity of the term “SSGs,” it was used interchangeably with the term “conditioned games” in this survey. Hence, irrespective of the particular format of play employed (e.g., 1v1 without goals, 5v5 with regular goals, 10v10 on half the pitch), all these activities were collectively categorized under the umbrella term of SSGs. This categorization was based on their shared design, which incorporates task constraints aimed at emphasizing specific behaviors and achieving desired player outcomes while preserving the fundamental dynamics of the game.

Data acquisition and statistical procedures

The data gathered from the Google Forms survey was exported and compiled into an Excel file for analysis. For fixed response questions, a frequency analysis was conducted, which involved examining the distribution and frequency of different response options. This allowed for a quantitative assessment of the participants’ choices and preferences within the predefined response categories.

In the inferential analysis, the Chi-square test was employed to investigate potential relationships between two categorical variables, such as nationality and the survey question. When dealing with ordinal scales, the Mann-Whitney U test was utilized to assess differences between nationalities. These statistical tests were conducted using SPSS software (version 28.0.0.0, IBM, Chicago, USA), with statistical significance set at a p-value < 0.05.

When are small-sided games employed?

The popularity of SSGs in these countries can be attributed to various factors, including the influence of tactical periodization [27,30], a well-known training approach in Portugal, which emphasizes the use of drill-based games like SSGs to enhance player development across multiple levels. As a result, it is understandable that coaches frequently integrate SSGs into their training routines, although not necessarily in every session.

The substantial use of SSGs in training sessions aligns with the findings of a previous study that examined the training process of a professional soccer team over half of a season [21]. In that study [21], it was revealed that SSGs, in various formats, accounted for up to 39 minutes of the total training session time. This parallel supports the idea that SSGs have become an integral part of modern soccer training programs, playing a crucial role in developing players’ skills.

Considering the use of SSGs during warm-up routines can be attributed to their positive effects on athletic performance, particularly in terms of reactive agility, lower limb power, and sprint performance. Previous studies [31,32] have shown that incorporating SSGs into warm-up strategies can lead to improved acute athletic responses, which can be highly beneficial for preparing players for the demands of the subsequent training session or match.

By introducing technical and tactical challenges during the warmup phase, SSGs not only enhance the physical preparedness of players but also help to stimulate decision-making abilities early on in the training session [33]. This can be especially advantageous for players as they transition from warm-up to the main part of the training session, as they are already mentally and physically primed to engage in game-like scenarios.

During the main part of the training session, which occurs after the warm-up and before the cool down, it was evident from the survey that SSGs are widely implemented by coaches from both Brazil and Portugal, regardless of the phase of the season. In fact, in more than half of the training sessions, SSGs are utilized, indicating their versatility and potential to address various training objectives.

The flexibility of SSGs allows coaches to design training sessions with specific aims in mind. These games can be employed to develop technical skills [5], hone tactical behaviors [4], or enhance physical fitness [6]. The existing literature supports the positive adaptations that can be achieved through the use of SSGs, providing a sound rationale for coaches’ inclination to incorporate them into their training routines.

The popularity of SSGs in the main part of training sessions can be attributed to their effectiveness in creating game-like scenarios [1], fostering decision-making abilities, and promoting team cohesion. The dynamic and competitive nature of these games provides an engaging and challenging environment for players, contributing to their overall development.

The widespread use of SSGs in the main part of training sessions reflects the growing recognition of their efficacy among coaches. As the body of evidence supporting the benefits of SSGs continues to grow [3,6], it is likely that coaches will continue to integrate these games into their training methodologies.

Why are small-sided games chosen?

While Brazilian coaches largely emphasize that SSGs are crucial for developing attacking and defensive tactical principles, the majority of Portuguese coaches consider them important but not very important. Similarly, most Brazilian coaches view SSGs as very important for improving aerobic fitness and agility, whereas Portuguese coaches consider them important but not of the same high importance. These disparities in perceived importance may reflect variations in coaching philosophies, training methods, or tactical approaches in each country’s soccer culture.

Indeed, the observed differences between countries in the perceived importance of SSGs for specific components may be attributed to various factors, including differences in coaching education, available literature, or access to alternative training methods. However, it is noteworthy that SSGs are consistently considered important to very important for developing aerobic fitness, agility, technical skills, and tactical behaviors. This alignment with existing literature [6,34,35] highlights that coaches are well-informed about the advantages of using SSGs and are in line with recent evidence supporting their effectiveness.

Conversely, for improving strength, power, or sprint performance, coaches express less confidence in the utility of SSGs. This stance is also in line with existing evidence, which often suggests the superiority of other training methods for these specific physical qualities [7]. Coaches seem to recognize the need for more specialized and time-efficient approaches to target these capacities effectively, which may not be optimally addressed through SSGs alone.

How are small-sided games implemented?

The existing literature on SSGs’ ability to improve aerobic fitness and endurance performance has been steadily growing [6], with studies suggesting that SSGs can be as effective as continuous or intermittent running-based exercises in enhancing aerobic fitness. This finding has led to the popularity of SSGs, as they enable coaches to combine technical and tactical stimulus with an appropriate aerobic workout [15]. Particularly, the smaller formats of SSGs tend to induce heart rate responses exceeding 85% of maximal heart rate [36], making them effective in providing a significant aerobic stimulus. These findings offer valuable insights into the reasons provided by coaches, with 71.3% of Portuguese and 77.2% of Brazilian coaches expressing their positive use of SSGs for developing specific physical components. The high percentage of coaches employing SSGs for this purpose aligns with the increasing body of evidence supporting the effectiveness of these drills in enhancing aerobic fitness and other physical capacities.

The coaches’ preference for using small formats of play (1v1 to 4v4) for 11 to 20 minutes with imbalance formats to stimulate aerobic fitness aligns with the existing literature on the subject. The adoption of these specific training approaches by coaches indicates their awareness of the optimal conditions required to effectively target and enhance aerobic power in their players.

Smaller formats of play, such as 1v1 to 4v4, offer several advantages for improving aerobic fitness [15]. The reduced playing area and the increased number of high-intensity actions, including sprints, accelerations, and decelerations, create a more intense and demanding physical workload for the players [37].

Additionally, the use of imbalance formats, where one team has numerical superiority over the other, further intensifies the aerobic demands on the players [38]. The team with fewer players is required to cover more ground and engage in more frequent bursts of high-intensity movements, increasing the overall metabolic demand. Moreover, the coaches’ selection of an 11 to 20-minute duration for SSGs is well-founded. Research suggests [6] that this timeframe is adequate for eliciting physiological adaptations and promoting positive changes in aerobic fitness.

It is noteworthy that coaches frequently employ smaller formats (1v1 to 4v4) of SSGs to stimulate change of direction in soccer players. The rationale behind this choice is rooted in the potential benefits of exposing players to the challenges of frequent changes of direction that occur in these game scenarios. While the heterogeneity of the number of accelerations, decelerations, and changes of direction in soccer is considerable [39], and some improvements in agility may be attributed to enhanced reaction time rather than a direct physical ability to change direction [40], studies have suggested that small-sided games can be effective forms of training to develop this skill [33].

Despite the lack of consistent research evidence specifically comparing changes of direction in small-sided games to multidirectional accelerations or sprints [35], coaches may believe that the specific demands of small formats can still contribute to the development of change-of-direction abilities in players. Indeed, agility is a multifaceted skill that encompasses perceptual-cognitive abilities, decision-making, and physical attributes. While small-sided games may not specifically target all aspects of agility, the repetitive exposure to rapid changes of direction in these game scenarios can still be beneficial for players. Coaches’ preference for using SSGs for change-of-direction training is likely based on the belief that regular exposure to such dynamic movements can lead to adaptations and improved efficiency in executing agile actions on the field.

Among the various physical qualities analyzed, coaches expressed less frequency in SSGs to improve linear sprint performance. This preference aligns with existing evidence suggesting that SSGs might not be the most efficient method for enhancing sprinting abilities in soccer players [7]. There are several reasons behind this trend observed among coaches.

Firstly, SSGs may not adequately expose players to high-intensity sprint actions, especially in smaller field formats [41]. In typical SSGs scenarios, the playing area is restricted, which may limit the distance players can cover at maximum speed [39]. As a result, players may not reach peak sprinting velocities during these games, leading to suboptimal training stimuli for enhancing linear sprint performance.

Secondly, the contextual demands of soccer matches do not always prioritize frequent sprints. Soccer involves frequent changes of pace, direction, and tactical decisions, requiring players to adopt various movement patterns. As such, players are not consistently exposed to sustained linear sprinting throughout a match, making SSGs less conducive to replicating this specific aspect of game performance [14].

The majority of coaches expressing their use of SSGs for technical skills development which is not surprising. SSGs offer a unique advantage of providing a high-intensity stimulus while seamlessly integrating technical and tactical aspects of the game. This characteristic makes them particularly attractive for coaches aiming to enhance players’ technical abilities within the context of realistic match scenarios.

Recent systematic reviews have supported this notion [34], showing that SSGs can be highly effective in improving individual technical skills, such as passing and dribbling, when compared to more analytical exercises. The dynamic and game-like nature of SSGs allows players to practice their technical skills in situations that closely resemble real-game scenarios, enhancing transferability to actual match performance.

Coaches predominantly expressed a preference for using smaller formats (1v1 to 4v4), which is consistent with the existing literature [5]. Smaller formats have been shown to increase the number of technical actions performed by each player within a given time frame [5]. This heightened frequency of actions in SSGs is likely to result in more opportunities for skill development and improvement following training interventions.

In the context of tactical behaviors, coaches also showed a significant preference for using SSGs as a means of improvement. Interestingly, in contrast to the preference for smaller formats in developing technical skills, coaches tended to opt for medium formats (5v5 to 8v8) for enhancing tactical behaviors. This choice is likely due to the larger formats allowing players to better emulate the model of play, enabling them to explore and practice important principles of the game, such as playing in unity and creating space in attack or fostering defensive concentration [4].

The analysis of task constraints and objectives employed by coaches revealed interesting trends in their preferences. Coaches tend to favor smaller fields for stimulating accelerations, decelerations, and technical skills, likely due to the increased diversity in movements and the proximity required for technical actions. On the other hand, coaches expressed a preference for using bigger fields to elicit physiological responses, promote more sprint actions, and facilitate the development of tactical behaviors.

These choices appear to align with existing evidence on the use of SSGs. Bigger fields have been shown to significantly increase players’ heart rate responses [16], making them suitable for targeting physiological fitness. Moreover, the larger playing area encourages more sprint actions, which can be crucial for specific training objectives [41]. Conversely, smaller fields may reduce the number of sprints but create a higher frequency of accelerations and decelerations [42], allowing players to practice precise technical skills.

The task objectives chosen by coaches offer valuable insights into their preferences for using specific SSG formats. Coaches primarily favored ball possession games for enhancing physiological stimulus, accelerations, decelerations, and technical actions, which aligns with the literature [43]. The emphasis on ball possession encourages players to constantly create space, leading to more frequent changes of direction and bursts of speed, as well as favoring players to circulate the ball more often, which increases the number of receives, passes, and dribbles.

For stimulating sprints, coaches mostly opted for penetration zones, which involve players overcoming a line or covering a specific distance with the ball as the primary objective of the task. This format provides opportunities for explosive bursts of speed and acceleration, contributing to the development of sprinting abilities.

In terms of tactical behaviors, the regular game format with a goalkeeper was the most favored option. This format closely replicates the conditions of a real match, encouraging players to apply tactical principles and strategies in a realistic context. The presence of a goalkeeper adds complexity to the task, requiring players to make decisions based on defensive and offensive scenarios.

Study limitations and future research

This study has several limitations that should be acknowledged. Firstly, as a survey-based study, the responses provided by coaches are subjective in nature, and caution should be exercised while generalizing the findings. Future research could consider complementing the survey data with direct observations of coaching practices in clubs to triangulate the information.

Additionally, while the survey had a considerable number of participants, it focused solely on coaches from Portugal and Brazil. The training philosophies and coaching education programs in these countries might differ from those in other regions, limiting the generalizability of the findings to a broader international context. Therefore, caution should be exercised when applying these results to other countries or regions.

To overcome these limitations, future research endeavors should endeavor to broaden the survey’s scope to encompass coaches from diverse cultural backgrounds and geographic regions. Indeed, training approaches, models, and styles can vary significantly from one country to another. Therefore, it is essential for future research to extend the survey to encompass various regions that may employ distinct training methodologies. This will enable a more comprehensive and comparative analysis of coaching practices worldwide. The completed survey is available in supplementary file 1, facilitating its replication in different contexts and offering researchers the opportunity to compare results with our findings.