The objective of this study was to examine how French adolescents accumulate MVPA according to their PA profiles, at different social occasions during the day. The three main results were that: (a) the PE lesson provides the best MVPA opportunities in all profiles, (b) school and at home represent the longest times spent in social contexts, but provide low opportunities for MVPA, and (c) participants in the HEPA active profile manage to seize MVPA opportunities at many social occasions compared to participants in the other two profiles.
The big gap to engage in MVPA: a mismatch between duration and opportunity ratio for PE lesson, school and at home
Results showed that the PE lesson exhibited the highest opportunity ratio values, thus representing the most opportune social occasion to engage all adolescents in MVPA. These data confirmed those reported by Sanz Martin et al. (2021) and Gavarry et al. (2003) who showed that, on the day the PE lesson took place, adolescents engaged in more MVPA [30, 31]. However, its opportunity ratio level, between 23.6% (HEPA active profile) and 14.7 (inactive profile) was rather low and confirmed the systematic review of Burson et al. (2021) showing that only 31% of the PE lesson is consecrated to MVPA . Its duration in the week (95, 34 and 96 minutes per week for each profile) was insufficient to ensure enough weekly MVPA levels [8, 33]. While the literature was rich regarding pedagogical methods to increase adolescents’ MVPA , the discrepancy between participants in terms of opportunity ratio values (23.6% vs 13.8%, p < .05, for HEPA active and inactive profiles respectively) suggest the need to (a) develop specific teaching strategies according to each PA profile in PE , (b) increase PE time per week, and (c) inform parents and adolescents to the actual amount of MVPA during PE classes to ensure they are aware of the need to engage in the MVPA on other social occasions to reach the WHO’ guidelines.
The time reported in PE lessons for the minimally active profile (34 minutes per week) seems low considering that at this age, a minimum duration of PE is set at a standard of 120 minutes per week in the French education system. This difference of engagement, compared to values reported by HEPA active and inactive students, is hard to explain from the data and could perhaps be attributed to the disruptions brought about by the COVID-19 (CV19) pandemic, which interrupted PE lessons in some classes and not others . However, as we were mostly interested in identifying opportune times for MVPA, we believe that this anomaly does not negate our conclusions.
Home (5.3% vs. 0.0% vs. 0.0% for HEPA active, minimally active and inactive profiles respectively) and school (2.4% vs. 0.0% vs. 0.0%) represent the venues for the two social occasions with the significantly lowest opportunity ratio values. Logically, the higher the duration of social occasions, the lower should be the opportunity ratio values, corroborating previous studies showing that school time tends to promote sedentary behaviors during the day [37, 38]. Paradoxically, school has been considered as the most appropriate place to promote a PA lifestyle for adolescents [39,40,41]. Brooke et al. (2014) have shown that adolescents had a total PA level lower in school, than out of school, with the possibility of accumulating even more in it . Weaver et al. (2021) have shown that MVPA has shown increases during school time since 2015 . Therefore, it seems apparent that the pedagogical challenge consists of tailoring programs to impact on minimally active and inactive adolescents during school time, including PE time in this strategy. Focusing on home social occasion, result highlighted the importance of the time spent at home to accumulate MVPA. Without quality support, adolescents did not engage independently in this social occasion, which was a significant part of their week.
The “HEPA active” profile: a population model to seize MVPA’ opportunities
One of the main findings of this study was that participants in the HEPA active profile managed to accumulate higher values of MVPA than participants in the two other profiles on many social occasions, including: home, PE lesson, recess, relax, school, transport, autonomous and supervised leisure (p < .05 and ηp2 > .14). These social occasions seem important to move from inactive to HEPA active profile. Considered as “a role model group” in terms of MVPA, analysis of participants with the HEPA active profile have shown an ability to optimize social times for undertaking MVPA, compared to participants in other profiles.
Except for PE lesson, the two higher values of the opportunity ratio for HEPA active adolescents were transport and recess social occasions (respectively 12.9 and 9.4%). Level of transport supports the rationale for promoting use of methods of active transportation to tackle the decline in PA in the adolescent population. Booth et al. (2014) have reported a downward trend in active transportation use among adolescents over the past two decades . Conversely, several intervention studies with environments built around cycling to school have shown positive results in terms of increasing MVPA [44, 45]. Focusing on recess time results have reinforced the importance of this scholarly time in high school to promote MVPA, confirming findings in studies focusing exclusively on younger children (primary and secondary schools) with playground facilities [46, 47]. Thus, our results reinforced the need to promote both active recess periods during school and active transportation before and after school.
Autonomous leisure, home and relax social occasions, demonstrated the ability of HEPA active participants to accumulate MVPA on their own during free time, despite displaying a lower ratio than the median value (respectively 6.1, 5.3 and 3.4% vs 6.9%). These results were in line with current French studies that show a shift in PA practice among adolescents towards free activities without constraints [48, 49]. These results corroborate the low opportunity ratios of supervised leisure social occasion (2.8, 0, 0% for each PA profile), perceived as collateral damage of these new unconstrained practices. Specifically in adolescents, previous studies have shown that sports participation was socially stratified, for example regarding school program , gender [50,51,52] or parental PA participation . This study did not consider socioeconomic status and the relationships that parents have with PA but outlined that this supervised leisure time could also provide opportunities to increase MVPA levels.
It is worth noticing participants in the HEPA active profile accumulated MVPA on five social occasions which were totally ignored by participants in other two profiles, while their absolute duration values were almost identical: home (5.3% vs 0% vs 0%), relax (3.4% vs 0% vs 0%), recess (12.3% vs 0%vs 0%), transport (9.4% vs 0% vs 0%) and autonomous leisure (2.8% vs 0% vs 0%). To the best of our knowledge, this result is a novel contribution to the literature, since, so far, studies have mainly analyzed MVPA through the filter of individual determinants of the ecological model (i.e. gender, age, BMI), but rarely by daily social activities [53,54,55]. This new knowledge reinforces the idea of the importance of education to invest maximum opportunities in a large variety of social occasions, to facilitate individuals to achieve the levels stipulated in the World Health Organization (WHO) guidelines for MVPA . This ability remains one of the most common goals targeted by PE teachers around the world : educate to a physically active, healthy, and sustainable lifestyle [48, 57]. Individuals with a HEPA active profile seem to represent the more physically literate students, and it would be interesting to examine which kind of physical, cognitive, social, and emotional skills and attributes they exhibit . It seems necessary to conduct more longitudinal studies to verify whether they will, in the future, be able to “value and take responsibility for engagement in physical activities for life” .
Creating new social opportunities to fostering MVPA in all adolescents
One other interesting result was the different use of social occasions to accumulate MVPA according to the adolescents’ profiles. The literature has documented consistently that “lack of time” was one of the most frequently reported barriers to engagement in PA [9, 10]. However, our results showed that HEPA active adolescents were able to seize MVPA opportunities in different social occasions, allowing them to reach the recommended PA thresholds. The question of how to promote PA during unsupervised social occasions appears to be key in fostering MVPA in the minimally active and inactive adolescents. It also offers a new perspective for designing PA promotion in an ecological framework [14,15,16] where the chronosystem would not be considered as continuous, but rather in terms of opportunistic times. Distinctions between the duration and the MVPA opportunity ratio according to the adolescents’ PA profiles demonstrated the need to revisit this ecological model where temporality has, until now, been perceived as linear (chronos) when it would appear to be better considered as in terms of opportunistic moments (kairos). Both educational interventions and territorial disposition for MVPA engagement should be rethought by including “social occasions exploration” to achieve better health outcomes. School curriculum for PA levels among adolescents could be further informed by these findings. It raises the question of adolescents’ exploration of social occasions, opening the way for further qualitative studies to identify conscious and unconscious processes of MVPA engagement during different social occasions.
To the best of our knowledge, little is known about the relationship between time perception and PA opportunities among adolescents . Time has been almost considered as a pre-defined period of chronological segments to depict patterns of PA among adolescents [12, 61, 62], rather than as a perception of opportunities for PA. This vision of social occasions considered as affordances (an “invitation”) to develop PA  is needed to better understand PA behaviors in adolescents and tailor strategies to promote PA in this population. The way an individual uses their time can greatly affect their health and results of this study showed the relevance of exploring maximal social times to meet the requisite PA levels stipulated in WHO guidelines. This time question associated with PA has been already framed by the concept of time perspective  which represents the personal attitude toward past, present and future times; or the concept of elasticity of time  in order to understand ripple effects when time variation in one activity (MVPA) affects the others. Our results encourage future studies to focus deeply on the question of use and perception of time to develop MVPA among adolescents.
The strengths of this study are based on the measurement of MVPA by accelerometry and its limitation is in the documentation of social occasions by self-reported questionnaire. The category of “other” referred to all social times when participants were awake, that could not be reconstructed by the logbook. The HEPA active adolescents seemed to be more assiduous than the minimally active and inactive in providing information in their logbooks. Finally, as with all current studies of PA among young people, the context of the CV19 pandemic has had a significant impact on active behaviors. Future studies will need to be conducted to verify whether the trends reported in this study will continue in conditions outside the pandemic.