The main finding of the study was that exclusive use of snus is associated with higher intensity sport activity. Respondents with higher sports activity reported lower odds ratios for cigarette smoking than those not engaged in sports. Dual use seemed to be more common among males actively engaging in sports than among those who do not engage in sports. In particular, persons training several times a week in a team sport like ice hockey, reported higher prevalence of snus use and dual use.
Possible explanations for increased snus use among physically active persons are that snus use is perceived as a less health-damaging form of tobacco use, it is thought to be less harmful to oxygen uptake compared to smoking, or that its negative health effects are poorly known. Sports requiring more individual performance and maximal oxygen intake (e.g., running, swimming, cycling, and cross-country skiing) were not associated with any tobacco product use. Consistent with previous studies [7
], we found that snus use was related to physical activity organized by sports clubs or teams suggesting that snus use is somehow promoted or even distributed in these environments. These issues must be more thoroughly investigated in further studies. In the sphere of team sports, peer relationships and social support are crucial components. Based on theories of health behaviours, social norms are important in determining the behavior of individuals [16
]; if individuals perceive a certain behaviour to be common among their peers and feel that it is important to conform to social norms, they are more likely to engage in that behaviour themselves than would otherwise be the case.
When joining the EU in 1995, Finland applied for a total ban on snus sales, which explains why access to snus is more difficult than access to cigarettes. Snus is, however, easy to import for personal use from neighbouring Sweden, where manufacturing and selling of snus is legal [11
]. "Personal use" is defined by Finland as such a large number of snus packages, however, that it is possible to organise illegal sales of snus [11
], particularly when cruises to Sweden are common for Finns and snus is sold on the ferries.
During the study period (1999-2010), cigarette smoking decreased while snus use and dual use increased. It has been suggested that people, especially those actively participating sports, have changed from cigarette smoking to snus use. Based on our findings during the 11 years, however, the association between sports activity and smoking, snus use, or dual use remained stable. At least in young people who are just beginning their tobacco-use career, switching from one product to another does not seem to be important. The reasons for the increased snus use and decreased smoking in Finland remain largely unclear. Additional research is needed to determine the reasons for this development and whether snus is used as a method to quit smoking or whether snus use reflects changes in an individual's other lifestyle behaviours, such as physical activity.
The major limitations of the study are related to self-reporting and a cross-sectional study design. Although we cannot exclude the possibility of under- or over-reporting, studies have shown that, in general, youth provide valid reports of their tobacco use [18
] whereas they tend to overestimate physical activity [19
]. An important limitation of the present study is that military service is completed by approximately 80% of the age cohort and thus, despite the excellent response rate, the study population was slightly selected. It should be taken into account that 20% of this age group is suspended from military duty for medical reasons or choose civilian service. Another limitation is that we could not assess the exact frequency of snus use or number of cigarettes smoked using the questionnaires. It is, unlikely, however, that this would affect the comparison between different activity groups. Because of the cross-sectional design, causal inferences cannot be drawn from our results. We cannot conclude whether young boys learn the use of different tobacco products after engaged in e.g. team sports or whether there is a selection of different smokers or non-smokers to different sports activities. It is not possible to conclude either if different tobacco product use is adopted inside or outside the sports activities. Despite these limitations, this study has notable strengths. The study had a high response rate and is unique because we were able to test the evolution of the associations between tobacco products use and physical activity over a long period of time (1999-2010).
In conclusion, our findings indicate that the use of snus is associated with higher sports activity and that persons with higher sports activity report lower cigarette use than those not engaging in sports. In particular, persons training several times a week in ice hockey or other team sports reported high levels of snus use and dual use. Sport events requiring maximal oxygen intake (e.g., running, swimming, cycling, and skiing) were not associated with tobacco product use. Although the association between snus use and team sports requires more research, preventive measures concerning tobacco product use may be targeted to sports clubs.