Do adolescents' experiences of the barriers to and facilitators of physical activity differ by socioeconomic position? A systematic review of qualitative evidence

This review aims to systematically identify and synthesize qualitative data on adolescents' experiences of the barriers to and facilitators of physical activity to understand whether these differ by socioeconomic position. Multiple databases (MEDLINE, Web of Science Core Collection, PsycINFO, and ERIC) were searched in August 2020. Duplicate title/abstract and full text screening was conducted. Studies were included if they reported qualitative data collected from adolescents (aged 10–19), a measure of socioeconomic position and focused on physical activity. Studies not published in English or published before 2000 were excluded. Relevant data were extracted and methodological quality assessed (in duplicate). Data were analyzed using Thomas and Harden's methods for the thematic synthesis. Four analytical themes emerged from the 25 included studies: (1) social support, (2) accessibility and the environment, (3) other behaviors and health, and (4) gendered experiences. These themes appeared across socioeconomic groups; however, their narratives varied significantly. For example, provision and access to local facilities was discussed as a facilitator to middle and high socioeconomic adolescents, but was a barrier to low socioeconomic adolescents. These findings can be used to inform how different socioeconomic groups may benefit from, or be disadvantaged by, current interventions.

Restrictions in response to the Covid-19 pandemic, including national and regional lockdowns, social distancing restrictions, and the closure of schools and sports clubs, 7 have exacerbated inequalities in obesity and physical activity. 8 As we move toward recovering from the pandemic the challenge for public health professionals is to identify effective and equitable strategies to prevent obesity, through, for example, promoting physical activity. Understanding socioeconomic variation in physical activity is important to achieving this goal, as it may represent a pathway by which socioeconomic position (SEP; socially derived economic factors that influence what position individuals or groups hold with society 9 ) leads to overweight and obesity. 10 However, while a positive relationship exists between SEP and physical activity in the adult population, 11,12 it is much less discussed with regard to adolescents.
At present, within the relatively small body of literature that has directly examined the association between SEP and physical activity, findings are equivocal. A systematic review of this evidence suggests that a higher SEP is associated with higher levels of physical activity in adolescents. 13 However, 42% of studies reported no association or an inverse association between SEP and activity levels. Reasons for these results are that studies used (1) varying indicators of SEP, (2) subjective, self-reported measures of physical activity, and (3) varying domains (e.g., active travel and leisure time) of physical activity. However, the relationship between SEP and physical activity remains unclear even when using a standardized measure of SEP and harmonized accelerometer data. 10 It is possible our incomplete understanding of this relationship is contributing toward the reported limited efficacy of interventions to promote physical activity among this population. 14 Social ecological models describe the interactive characteristics of individuals and their environments that underlie observed health outcomes and have long been recommended to guide public health practice. 15 This aligns with the conclusions of previous research, which suggests there is no single explanation for a relationship between physical activity and SEP during adolescence. 13 It is therefore important to identify and understand factors related to physical activity behavior and how they vary by young people's personal circumstances. 16 Investigating the correlates of physical activity has contributed to this, and there are several systematic reviews of quantitative evidence [17][18][19][20] based on the behavioral epidemiology framework and socioecological models. 21,22 However, as the need to listen to young people has become increasingly emphasized in public and political debate, 23 there has been an increase in qualitative studies offering a distinct understanding of adolescents' perspectives and experiences of physical activity. 23 Understanding these experiences and how the barriers and facilitators of physical activity might be shaped by circumstance and context may provide new insight on this complex relationship. 24 In response, this review aims to systematically identify and synthesize qualitative data on adolescents' experiences of the barriers and facilitators of physical activity to understand whether these experiences differ by socioeconomic position.

| METHODS
A protocol for this systematic review was registered on PROSPERO on June 30, 2020 (CRD42020179997). The Enhancing transparency in reporting the synthesis of qualitative research (ENTREQ) checklist was followed to guide this review paper. 25 There are numerous ways to describe and measure socioeconomic conditions. This becomes especially evident in research with children and adolescents where proxy measures such as parental education or income are used. 26 In this review, we use the term SEP to refer to numerous exposures, resources, and susceptibilities that may affect health, acting as an overarching definition for multiple indicators. 27 Table 1). The full-texts of the remaining articles were obtained for duplicate screening. Due to a high volume and heterogeneity of studies remaining, the review team agreed on revised in/exclusion criteria (specified in Table 1) and rescreened all included articles. Conflicts were discussed at all stages, and a third member of the review team was consulted if a consensus could not be reached.

| Quality appraisal
The methodological quality of included studies was assessed using the Critical Appraisal Skills Programme (CASP) qualitative checklist. 30 The CASP checklist was selected as it is user friendly and widely used, allowing the results to be compared with other reviews. 31 Two authors independently appraised 10% of the studies as a calibration exercise and to check agreement. One author appraised the remaining articles against the criteria outline in Table 2. While CASP is widely used, there is still no commonly agreed upon appraisal tool; therefore, studies were not excluded based on this.

| Data extraction
The following data were extracted into a data extraction template using excel: bibliographic information (author and country date), study aims, methods (participants, data collection, and analysis), measure and level of SEP, presentation of results, barriers to physical activity, facilitators of physical activity, and conclusions and implications for policy and practice. The table also included a "notes" section where authors could highlight potentially additional useful information from the introduction and discussion of each article to support data interpretation. Data extracted under the "barriers" and "facilitators" T A B L E 1 Inclusion and exclusion criteria of study eligibility  (4) headings were extracted verbatim from the "Results" section of each paper. This included first-order (adolescents' quotes) and second-order constructs (researcher interpretation, statements, assumptions, and ideas). 32,33 Two members of the review team independently piloted the extraction form. After modifications were made, the same two reviewers independently extracted data from 10% of the articles. A high level of agreement was reached (authors extracted the same information from both articles, with some variation in the level of detail); therefore, both reviewers continued to work independently to extract data from the remaining articles.

| Data analysis
One member of the review team analyzed the extracted data following Thomas and Harden's 33 methods for the thematic synthesis of qualitative research in systematic reviews. This method was chosen as the synthesis product is conducive to producing recommendations for policy and practice. 34 The synthesis involved the steps described below.
In step 1, one author re-read the extracted results from each paper to become familiar with the data and allow codes to emerge inductively. This informed an initial bank of codes based on common barriers and facilitators identified across studies. In step 2, the same were included (see Figure 1).   Table 2 presents the summary ratings for the quality assessment.

| Quality assessment
Included studies were all of high quality. Notable limitations were that 48% of studies did not report considering the relationship between the researcher and the participant and 24% of studies failed to provide a reflection on the key ethical challenges.

| Results of the thematic syntheses
Four analytical themes were identified: (1) social support, (2) accessibility and the environment, (3) experiences of health and other behaviors, and (4) gendered experiences. Please see Table S1, which documents how codes where developed into descriptive and then analytical themes. These themes appeared across socioeconomic groups, however the way in which they supported or prevented engagement in physical activity differed by SEP. A summary of the themes by SEP can be found in Table 4.

Low-SEP adolescents
A lack of financial support was a commonly mentioned barrier to physical activity among low-SEP adolescents [35][36][37][38][39][40][41][42] (e.g., "my parents don't have money … to have membership of a sport club"). 41 Low-SEP adolescents reported that the cost of physical activity made it difficult for them to participate, as it was an additional expense their parents could not afford. For many parents, providing the basics, including school uniform was a struggle, with physical activity viewed as a "non-essential" expense. 35 In general, adolescents were accepting of this and understood that their parents could not provide them with physical activity opportunities requiring fees.
However, some adolescents communicated a desire for their parents to be more proactive in signing them up for low or zero cost local activities, "I wish she would sign me up to play more things at the YMCA." 43 A lack of transportation was another commonly mentioned barrier. 44 35 In the majority of studies, adolescents did not see this as problematic and were content with more sedentary activities.
However, some desired more encouragement than they were currently receiving 40 36,40,46 The addition of a step-parent also influenced the family dynamic, as adolescents perceived parents to become more partner-centric. 43,47 While narratives around support were primarily negative amongst low-SEP adolescents, there were some instances where support was described as facilitating physical activity. A few explained the great lengths their parents went to in supporting their physical activity involvement, which often came at the expense of their parents' own activity.

Middle-SEP adolescents
Middle-SEP adolescents described how their parents would drive them to places rather than encourage them to engage in more active kinds of transport. 54 Furthermore, not having friends to walk to school with added to the allure of being driven: "Mostly I'm driven in the morning but can walk home." 54 Financial support from parents to provide adolescents with mobile phones was commonly reported to facilitate physical activity. 54,55 Owning a mobile phone "in case of an emergency" increased middle-SEP adolescents' opportunities to be active. 54

High-SEP adolescents
Amongst high-SEP adolescents, parental encouragement to "opt out" of physical activity, and focus on academic attainment/work, was often communicated as a barrier. 42,56 In one study, all participants confirmed that their decision to opt out of school physical education (PE) was to focus on academic work. 56 These adolescents felt that physical activity was nice to do, but achieving in "academic subjects" was a necessity and felt this kind of academic pressure was far greater in private schools.
The way that I was raised and the way my parents think, they made me focus on academics … with athletics and arts sort of like they are great to have, but your main focus should be academics … 56 This academic pressure extended to "CV building" activities. 56 Adolescents reported having little free time to be active amidst their other activities, such as volunteering or band practice. Parents were said to be responsible for timetabling, which acted as an instrumental barrier to becoming more active.
Peer pressure to "opt out" of physical activity was reported as an additional barrier. 56 While academic pressure was common amongst high-SEP adolescents, the narrative in this group tended to focus on the support they received to be active. Financial support from parents was a frequently mentioned facilitator. 47,55,57 This support was required for specialized clothing, equipment, and club membership, "My parents pay for it (specialized clothing and equipment) so I suppose without their help I wouldn't be able to attend my training sessions." 47 Furthermore, participating with friends was reported to make physical activity more enjoyable. 36,41,55,56 High-SEP adolescents explained how their parents encouraged them toward certain types of physical activity. These activities took the form of organized sports clubs where parents were also involved, 41,56 "I got involved (in netball) because my sister used to do it when she was young … I used to go and watch her … it looked good fun." 41 Parental transport was a facilitator for many adolescents. 41 Parents often stayed for the duration of the sports practice or match, offering further support and encouragement. 47 Participation in family activities such as walks in the countryside were also frequently mentioned. 41,55 Comparing and contrasting across the socioeconomic groups Support for physical activity was identified as a key theme, however its role differed by SEP. Adolescents reported their parents to have the largest influence over their activity behavior, but for many parents, physical activity was low on their list of priorities. For low-SEP adolescents, this was due to a lack of time and money and the prioritization of other aspects of life, for example, spending time with a partner or needing their child to help around the house. For middle-SEP adolescents, this was due to their parent's prioritization of less active modes of transport, and for high-SEP adolescents due to their parent's prioritization of academia.
One of the starkest differences across socioeconomic groups was family participation. Middle/high-SEP adolescents frequently mentioned a "whole family" approach to physical activity. This was not the case for low-SEP adolescents who were more reliant on support from teachers and coaches.
Peer support was an important facilitator across all groups, especially for making physical activity more enjoyable. In addition, low-SEP adolescents relied on their friends for additional kinds of support e.g. scheduling reminders.

Low-SEP adolescents
Low-SEP adolescents commonly mentioned the limited provision of facilities in their local neighbourhood. [35][36][37]41,45,52,57 and often referred to facilities outside their local area, in more affluent neighborhoods.
"There aren't many options within our community.
There's some martial arts, but that's it." Another low-SES student commented, "There's no place like that around here, we have to go to the other side of town." 36 Adolescents' access to these facilities was impacted by the quality and safety of local public transport. Many described fear and anxiety around modes of transport such as taking the bus. 36 In addition to their local environment and facility access, low-SEP adolescents reported that similar barriers existed in their school environment. 41,46,57,58 This included a lack of school facilities leading to limited physical activity options and opportunities, or a complete absence of physical activity in their school. 40 Adolescents also emphasized the importance of neighborhood safety as it meant their parents allowed them more freedom.
The kids around here are very active because there're so many parks around here and it's a really nice neighbourhood … It's one of the most safe neighbourhoods, so I could walk outside, like really late at night. 55

High-SEP adolescents
A common narrative among high-SEP adolescents was the variety of physical activities they had access to, at school and in their local neighbourhoods. 36,42,55,56 School provision covered activities ranging from team sports such as basketball, rugby and hockey to more exclusive activities including ski trips and mountain biking. One adolescent explained, "the school has links with a lot of clubs so it is easier to join." 41 Adolescents discussed how their schools promoted physical activity outside of school hours by encouraging their students to join sports clubs. 41 Regarding their local neighborhood, high-SEP adolescents explained how where they lived facilitated their involvement in physical activity. 55 This included their access to the countryside and the provision of sports clubs and facilities in their local area. 36,41 I think this area (around School A) gives plenty of opportunity to take part in physical activity, there is a local swimming pool… plenty of parks to play football… tennis courts… plenty of local private clubs…. 41 Comparing and contrasting across socioeconomic groups

Low-SEP adolescents
Among low-SEP adolescents there was some confusion around the definition of physical activity, for example, "playing video games by using fingers makes your hands tired." 57 However, in general low-SEP adolescents discussed their understanding of the health benefits of physical activity as a facilitator and communicated a good understanding of the mental and physical health benefits. 40,48,50 Burning calories was a frequently reported motivator which encouraged adolescents to engage in physical activity, 43,48 "If you walk, like maybe a mile or two to the nearest grocery store, you lose calories." 48 Low-SEP adolescents also described how being active was good for the environment and reported this to further facilitate their motivation to be active: "… trying to be more active for the environment … and help with environment and pollution and stuff like that and health-wise." 48 Physical activity was positively discussed in relation to mood, with active individuals perceived to be happier. 43,58 Middle-SEP adolescents There was little discussion around the health benefits of physical activity among middle-SEP adolescents. Other behaviors were discussed to take priority 54 and physical activity was viewed as a barrier to these. Other engagements were also discussed as a barrier to physical activity and included new social demands and changing groups of friends. 42,54 High-SEP adolescents The health benefits of being active were recognized by high-SEP adolescents, however physical activity was viewed as a barrier to other behaviors which adolescents prioritized. Free time was discussed as a limited commodity due to academic and extra-curricular demands and time which was considered valuable for activities such as sleep or getting caught up on homework. 36,42,56 Comparing and contrasting across socioeconomic groups The health benefit of physical activity was a dominant narrative among low-SEP adolescents, who discussed its positive impact on both long and short-term health as a facilitator. This was not the case for middle-and high-SEP adolescents who saw physical activity as a barrier to other behaviors.

Low-SEP adolescents
Low-SEP adolescents considered how their gender acted as a barrier to or facilitator of physical activity. When discussing physical activity, females voiced concerns about their appearance, body image and self-confidence. 38,42,58 For some girls, reports of bullying and attacks on their weight lead to negative experiences of physical activity.
I don't like PE because I am self-conscious and a lot of the boys hang things on you. When my friend Sally is running and that, the boys say that is gross. 43 Low-SEP adolescents also reported low self-esteem and anxiety around physical activity. 38 45,48 This was reinforced by the parents of adolescent girls, who were reported to discourage their daughters from engaging in active transport for the afore mentioned reasons. 48 Gendered parental attitudes extended beyond active transport, with parents reported to place unequal demands on females when it came to household chores and homework, leaving them less time to be active. 36,38,44,58 Adolescents also spoke of how their parents viewed sport as "not for girls" and how females had fewer opportunities to be active due to a lack of female role models and activity provision, "There is more for boys; soccer, for example, that is a sport for boys, I think … You see more guys playing soccer on TV." 37 Linking with themes around stereotyping, low-SEP females felt insufficiently supported by their family to be physically active. 38 They also reported a desire for their friends to be more supportive. 49 However, this was not the case for males, who expressed satisfaction with the support they received from peers and felt encouraged to be active by their parents and relatives. 38,59 Low-SEP males described sports where they could demonstrate skill to facilitate their likelihood to engage in physical activity, "If the whole thing was sports, I would go," "Oh, like if I practise a lot, I want to show it off." 51 This aligned with the perceptions of females, who discussed how they disliked being physically active with boys, as they were only interested in performing and showing off, "Boys want to be ball hogs…," "Boys think they can do things better than girls." 51 While females voiced a preference for participating in physical activity with other females, males did not have the same preference and enjoyed mixed-gender activities, 51 "I think it should be good to do it with girls in the group because they know all the stuff." 51

Middle-SEP adolescents
Among middle-SEP adolescents, it was those who described themselves as inactive who discussed gendered experiences. 42

| Strengths and limitations
This review responds to identified gaps in current evidence. 16 As the first review to systematically assess socioeconomic difference in adolescents' perspectives of the barriers to and facilitators of physical activity, we provide contextual information broadening current understanding of the relationship between SEP and physical activity during adolescence. Strengths include the use of multiple databases, systematic and rigorous review methods and the assessment of methodological quality. We acknowledge several limitations. Only peer-review studies published in English were included and this may have led to the exclusion of relevant articles. As there is no commonly agreed upon appraisal tool for qualitative research, 78 we did not apply an exclusion criterion based on quality, but all included articles were deemed to be high in quality. In line with recommended methods, 33 our data extraction included all data in the "Results" section of each paper. As the data reported in these studies may have been selective or biased, this may have affected our synthesis. Furthermore, the majority of included studies used area-level indicators of SEP (neighborhood or school level) as a proxy for individual-level SEP. This is common in adolescent literature where individual-level SEP is difficult to determine, 9 but this may lead to the assumption of socioeconomic homogeneity within areas, raising the question of "ecological

| Implications for policy and practice
Various policy documents have called for the development of effective strategies to increase physical activity in adolescents, to help halt or reverse the increase in obesity and improve other aspects of health. 80 The convergence of the childhood obesity epidemic and the Covid-19 pandemic increases the urgency to respond to these recommendations and supporting those of low-SEP should be recognized as a priority.
This review identifies inequalities in barriers to and facilitators of physical activity across individual, social, environmental and societal levels and supports the ecological approach to behavior change. 81,82 To effectively promote physical activity, professionals should consider intervening on multiple levels while accounting for the contrasting needs of socioeconomic groups. Specific emphasis should be placed on inequalities in structural environmental or policy changes supporting increased facility provision and environmental regeneration in more deprived areas.
This review also highlights the public health potential of multicomponent approaches which include the family, by considering how parental factors and the home environment influence physical activity. 16,63 For low-income families this involves considering parents' lack of time and resources. Furthermore, this review highlights that PE professionals can have a significant role in creating physical activity opportunities and establishing links with the community, especially for low-SEP adolescents. In order to facilitate this, schools with a high proportion of low-SEP adolescents should be recognized by policy makers and public health professionals as having an important role to play in improving young people's physical activity. 83 Peralta et al. 83 suggest low-SEP schools achieve this through a whole school approach to overcome student inequality, with a focus on each of the three domains of the health-promoting schools framework: (1) health education in the curriculum; (2) changes to the school ethos and physical environment; and (3) involving families and/or communities to support health promotion. 84 In addition to SEP, intervention development and policy decisions should consider gender differences in this age group. Our findings support the need for continued investment in interventions targeted at females, 16

SUPPORTING INFORMATION
Additional supporting information may be found in the online version of the article at the publisher's website.