Our data indicates that playing soccer was more associated to HED in the previous month compared to non-playing sports. Compared to other team sports, soccer practice was also more related to HED. Yet compared to other team sports, soccer players with the lowest and highest frequencies of practice as well as those motivated for pleasure and for profession were more prone to report HED. This data confirmed our primary expectations of soccer players being associated to HED and that frequency and motivation for practice are differential factors when predicting HED. Regarding preferred beverages, drinking partners and places for drinking, subtle differences were observed in our study. All groups studied reported beer as the most preferred beverage, drinking mostly with friends and nightclubs or bars being the most common setting.
Soccer was more associated with HED in the last month when compared to non-practicing sports. Similar results were observed by previous studies that pointed to a high level of alcohol consumption among high school students who played sports or practiced physical activities [9–11]. The importance of social contexts of sports practice for drug use were highlighted recently by other another study . Socialization aspects of adolescent development may exert some influence on the relationship between sports practice and alcohol use. Studies showed that peer norms have an important role in physical activity behavior among adolescents  and peer group pressure is a predictor of substance abuse . Accordingly, it is expected that once alcohol consumption is a part of normative culture, the adolescent could behave in a similar manner to that of their peers in order to promote the social bonds. Possibly when practicing soccer, adolescents are involved with older peers, and being involved with older friends or acquaintances allows easier access to beverages from this social source , favoring alcohol consumption, especially because in Brazil the legal drinking age is 18. Therefore, future studies should compare team and individual sports in order to explore collectivity and peer roles as an influence on alcohol consumption related to sports practice.
A previous study indicated that the induced sociability could be a more important factor than the sport practiced in relation to alcohol use . In team sport practice, the individual could be influenced by normative attitudes of the group. On the other hand, our data suggests that the practice of a team sport and its socialization aspects are not the only reason for higher HED reporting among adolescents. Soccer players were more likely to report HED than other team sports players. Soccer and beer are highly associated in Brazilian culture and this relationship apparently plays a fundamental role in alcohol consumption by adolescents. Even though partaking in sports is usually regarded as a healthy practice, there is evidence that culture exerts influence on sports players drug use, and its practice is often accompanied by alcohol use . Thus, the possible socialization induced by team sport practice itself cannot be directly assumed as a unique factor associated with the risk of HED, it being important to consider other aspects as cultural issues of the sports practice.
In our data, playing soccer for pleasure compared to team sports was associated with HED. A previous study that recreational physical activity does not provide much protection in terms of alcohol use . Pleasure, as a recreational motivation, is related to a lower commitment to the sport practice. Once the practitioner is not concerned about how much their performance will be impaired by alcohol consumption this could possibly promote drug use. On the other hand, adolescents who reported playing soccer as a profession also reported more HED than those with the same motivation and practicing other team sports. In contrast with those who play for pleasure, players with professional motivation for the practice tend to be more devoted to the practice. This motivation presumes a higher commitment to the sport. Therefore, these more athletic students could experience more stress and pressure associated with maintaining their dual activity, which could increase the risk for alcohol use .
Both highly active practitioners and those with the lowest frequency of practice of soccer were related to more HED. Independently of being highly or slightly active, soccer players were more prone to report HED. These results reinforce the idea of the strong cultural bond between soccer and alcohol. This connection seems to be so strong that regardless of the motivation (pleasure or as a profession) or frequency (1 to 5 days or 20 or more days per month), HED is more frequent among soccer than in other team sports.
In regard to HED characteristics, students independently of being non-players, soccer or team sports players reported beer as the most frequent beverage consumed. This beverage was previously reported as the predominant drink among adolescents in Brazil and several others countries [5, 36]. The beverages preferences among youth could promote a better understanding of related factors and more effective interventions could be tailored . Soccer players reported drinking more frequently than non-players or team sports students. Thus, they possibly could experience more the consequences of HED and be more likely to engage in risky behaviors.
Our results also indicated that all three student groups usually drink with their friends and at nightclubs or bars. It is also interesting to note that the adolescents also frequently drink with their relatives. Several studies pointed out the influence of parents and relatives behaviors and practices on adolescents drinking behaviors [38–40], including parents drinking behaviors . As parents and relatives are generally the most involved with the adolescents, their approval on drinking behavior may be important in explaining their alcohol use .
Several other authors have suggested sports-based interventions programs for specific groups, including high school students [7, 8, 42, 43]. Our study results suggest the need to consider the associated aspects of sports practice such as motivation, frequency and especially the culture, for intervention programs among this population. A recent study showed that sports clubs using accredited programs to reduce alcohol risk have a reduction in short and long-term risky drinking among members whereas clubs not using such programs have higher levels of alcohol consumption . This data suggests that tailored programs could be useful for reducing alcohol use, and our data could be integrated to improve future adolescent programs which aim to reduce alcohol consumption.
Strengths and limitations
This is the first study to assess the relationship between soccer and heavy episodic drinking among a representative sample of high school students from public and private schools of Brazilian state capitals. However, the results presented in this paper should be considered taking into account its strengths and limitations. This study is related to adolescents who were at high schools. Thus, our data should not be extrapolated to 14,7% of adolescents aged 15 and 17 that were not at school . In addition, our sample is representative from the 27 Brazilian state capitals, and adolescents from rural areas or country towns were not assessed.
Students might under-report their own substance use and students absent on the day of the survey could also have different patterns of alcohol use or sport practice. Furthermore, the data should be not directly extrapolated to other countries, especially those in which soccer is not a primary sport practiced. Notwithstanding, this study could serve as an example for other countries with a strong cultural relationship between sports practices and drugs use.
When multiple statistical comparisons are carried out, as in this paper, the impact of type I error inflation could be taken into account. Causality also cannot be assumed because there is no possibility to determine the directionality of the relations presented with this type of methodological design. However, cross-sectional studies can be useful for public health planning  and to guide preventive programs.
There are other variables that exert influence on drug use by adolescents (e.g. peer and parental influence) and that were not controlled for in this manuscript. Regarding the motivation variable, we speculate that separating health reasons from keeping fit could have some impact on results. These motivations involve different ways to face the practice of sport. Health reasons are often linked to a regular practice aiming at better general body functioning, while the practice oriented to keeping fit is more associated to aesthetics. However, we were not able to identify such differences. Future studies should be aware of this variable. Beyond that, this study did not differentiate exercise from physical activity. Physical activity corresponds to any body movement that results in energy expenditure whereas exercise is a repetitive and planned activity aiming a health improvement . In our case, exercise was not specifically measured.