According to the World Health Organization (WHO), children and adolescents (aged 5-to-17 years) should accumulate at least 60 minutes a day of moderate to vigorous intensity physical activity (MVPA) combined with vigorous-intensity aerobic activities at least 3 days a week. 1 Yet, in the latest Portuguese report card, approximately 70% of children and adolescents were failing to achieve those recommendations.2

Physical inactivity is in itself a pandemic, and a leading cause of death globally, responsible for up to 8% of non-communicable diseases and deaths across the world.3 At the same time, the benefits of physical activity on youth’s health are well documented, including improved physical fitness, cardiometabolic health, bone health, cognitive outcomes, mental health and reduced adiposity.1 Despite the large quantity of supporting data relating physical activity and, increasingly, sedentary behaviors to health outcomes across the life-span, there have been no improvements in global levels of physical activity since 2001.4 In fact, the prevalence of physical inactivity has increased in high-income countries, which already boast inactivity levels twice as high as those observed in low-income countries.3,4

Physical activity, in its simplest form, is completely free. Walking or cycling to school, and engaging in more outdoor (instead of indoor) play, offer an undeniable economic advantage compared to expensive memberships and costly sportswear. Nevertheless, a recent study confirm that physical activity intensity matters when it comes to achieve healthier body fat profiles and avoid excess adiposity, highlighting the need for children and adolescents to perform vigorous physical activity, which is increasingly more common when performing organized sports.5

The evidence for physical activity is compelling. So why is it that a quarter of the global population, and approximately 70% of Portugal’s youth, are failing to meet weekly physical activity guidelines? Determinants at many levels – including individual, social, environmental, and policy-related – may predict physical activity over time; and declined physical activity may be explained by different factors from those relevant to sustained inactivity. Information on these multiple determinants is useful in planning physical activity interventions while considering the distinct forms of active behaviors. Frequently, common tropes used by both the media and the public health authorities, promote the simplicity (or “simple steps”) of individual behavior change to enable more physical activity such as, walking to school or taking public transport, and walking in nature. However, those options often do not consider the environment in which people live. What if there are no green spaces nearby to walk or play? What if parents (and children) do not feel safe being outdoors? What if public transport stops are absent or unreliable? The social and physical environment in which people engage in daily activities has an immense influence on their choices and ability to easily choose the healthier option.

Those choices may be particularly challenged for disadvantaged communities, where opportunities for physical activity may be non-existent or unrealistic. The literature is clear when it comes to the social gradient with respect to health – the lower a person’s social position, the worse their health. In Portugal, the last decades have widened existing inequalities in obesity levels, which have significantly affected children from lower socioeconomic status.6 This may be partially explained by the 2008 global economic recession that severely affected the country. During the economic crisis, austere measures were implemented such as, the increase of taxes and the price of basic items, including better-quality food products, which may explain why families living in socioeconomically vulnerable areas stopped buying some products and started to buy cheaper food items.7 The current economic uncertainty, induced by the Brexit, the US-China trade tensions, the pandemic and the wars, may affect even harsher the  individuals with lower socioeconomic backgrounds, widening the already existing inequalities. But what do we know about inequalities in physical activity in the last decades?

Physical activity consists of different domains, such as leisure time, commuting and organized sport. These domains differ by their frequency, duration and intensity, and the nature of the physical activity. Children should obtain physical activity from more than one domain since different types of activities provide different health outcomes. Commuting physical activity, for example, is typically characterized as a moderate aerobic activity practiced either by walking or cycling from home to school, and has been associated with increased cardiovascular fitness.8 Organized sport typically takes place outside school hours, is directed by adult or youth leaders, involves rules and formal practice. This activity seems to be the major contributor to higher levels of vigorous physical activity in Portuguese adolescents,9 and has been associated with increased physical competence and social benefits.10

In Portugal, between 60 to 70% of school-aged children are enrolled in an organized sport.11,12 Our results clearly indicate that low parental socioeconomic status correlates with more difficult access to children participation in organized sports.11 The 2008 economic crisis (and probably the recent spike in uncertainty on economic activity) further widened the equity gap in children’s access to sport (lower impact of the crisis: 76.0% of children engaged in a sport vs. high impact of the crisis: 56.8% of children engaged in a sport).12 The coefficient of parental socioeconomic status on organized sports most probably relates to the resources needed to participate in sports clubs, including fees and equipment, since “cost” (followed by time) is a major barrier of 6-to-10 years old children’s sport participation reported by parents.13 These findings point to possible policy measures. For instance, reduced fees and sponsored equipment for children with a low parental socioeconomic status. Lower membership fees might potentially help to integrate children with low parental socioeconomic status into sports clubs and thereby make organized sports more accessible to all social classes. Low educated parents may also lack the awareness of existent funding opportunities,  which may help explain why financial barriers remain an important obstacle even in the presence of such funding. The same study found that the cost barrier to access organized sports was mostly reported by parents of girls. 13 The literature shows that parents seem to be less likely to purchase sporting equipment for their daughters compared with their sons,14 which may reflect some form of parental attributed importance of sport according to their child’s sex. Moreover, although information of actual sport activities price is not available in Portugal, sports usually preferred by girls may imply more costs to participate given the need for specialist equipment and facilities.

The sport-gender stereotypes of “sports divided into masculine and feminine sports” are prevalent around the world. This is also visible among Portuguese children. For instance, football is commonly seen as masculine, while dance and gymnastics are favored by girls. Although the prevalence of girls and boys performing sports is similar, girls have lower levels of team (and outdoor) sports involvement, and consequently lower levels of moderate  and vigorous physical activity, compared to boys.(15: in review) This phenomenon may be due to the common stereotype of team sports being a male-dominant activity, a lack of opportunity for girls to participate in team sports, a lack of diversity of sports offered in schools and co-curricular programs, or the girls’ lack of self-belief and confidence in sporting ability. During interviews with school-aged children, we found that sentences such as “I am not good at sports”, “I do not like to be active”, and “I am not interest in pursuing a career related to sport” were significantly more prevalent in girls than in boys.16 This may explain the dramatic decline in physical activity levels during childhood and adolescence, particularly among girls.

Lower levels of physical activity appear characteristic of the lifestyles of youth in most developed countries. We have found that a steadily increase of screen time with age, in Portuguese boys and girls aged 3-to-10 years old.17 Nevertheless, parental encouragement to be active and the parent’s own level of activity play a vital part on children’s sport participation, at least until the age of 11.13,18 The influence of parental modeling appears to be stronger in parent-child pairs of the same sex; 18 which may be driving the gender gap in participation. Targeting parents in order to increase their own physical activity levels may be an effective way to increase children’s activity.

As shown above, low-income children overall, but especially girls, seem to be least likely to be a current player, and most likely to have never played or dropped out. But what do we know about inequalities in other physical activity domains? The direct link between parental socioeconomic status and health-related behaviors may be more dissipated in unorganized physical activities. For instance, after adjustment to individual and family characteristics, school-aged children active commute was not associated with parental income or education, but positively associated with mothers actively commute to work, safety neighborhoods, and proximity to school.19 Nevertheless, a high-income household may indicate the ability to purchase material (e.g., bicycles) or may represent a residential environment suitable for children’s active commute and outdoor time.

Favorable attributes of the physical environment, such as access to recreational facilities, presence of sidewalks, controlled intersections, low crime rates, and area affluence may positively influence children’s physical activity. We have found that parents of girls also voice more safety concerns than parents of boys.13 This parental protective style may restrict children, especially girls, to perform activities without supervision and set physical activity space and/or time limits. Consequently, boys are more likely to be allowed to play outdoor alone than girls, while girls tend to accumulate more indoor play. Being active inside is great but it’s not a substitute for the great outdoors, mainly because indoor time is usually occupied with sedentary behaviors. There are important disparities in sedentary behaviors, including screen time. Children with few socioeconomic resources have greater access to televisions, computers, video games, and tablets in their bedrooms than children in higher income families.20

This article explores data collected in Portugal from 2002 to 2016/17, under multiple cross-sectional projects coordinated by researchers from CIAS, the Research Centre for Anthropology and Health at University of Coimbra. The projects have been described elsewhere.6 The inclusion criteria for the projects were the following: public or private schools from mainland Portugal; focused on pre- and/or school-aged children (3 to 11 years); and data assessed by different methods (each project may include more than one) such as, validated parental questionnaire, children interviews, accelerometers (e.g, ActiGraph), and anthropometric measures (e.g., height, weight, abdominal circumference). Information bias may have occurred in the parent-reported questionnaires (e.g., socially desirable answering). Physical activity also occurs in settings other than the home environment, and therefore parents’ report may be an underestimation of total behaviors. Moreover, socioeconomic status is a complex, multidimensional construct that can described and measured in numerous ways, and the results are context specific (e.g., due to the organization of sports and distribution of resources across social groups), so caution should be taken when generalizing the results to other populations.

Well-being is a fundamental human right and its promotion is a key objective of the WHO Global Action Plan on Physical Activity 2018-2030. Disparities in physical activity and sedentary behaviors foreshadow important disparities in health outcomes including obesity, diabetes, cardiovascular disease and premature mortality. Considering that the most sensitive period of the human lifecycle in which to promote long-lasting health-enhancing behaviors is childhood, youth education on active lifestyles and sport is deemed crucial. For this reason, is essential to understand and address social inequalities in physical activity participation across the life spectrum. Nevertheless, high status families may have resources (e.g., greater knowledge, stronger social connections, more economic resources) that leave them better positioned to capitalize – both money and time – on emerging interventions than those with low socioeconomic status, resulting in growing disparities.

Actions to encourage physical activity should be free or low cost, and must be implemented widely. Schools are a strategic place to promote physical activity to all, since the vast majority of children spend most hours of their day at school, and many schools already have the infrastructures and equipment necessary for sport activities. Promotions and interventions also should be tailored to diverse preferences across groups, encourage sports that have higher caloric expenditures, or identify sports that are most likely to be maintained as individuals age. Create an environment encouraging to physical activity is necessary, but this can only be made considering the influence and dynamic interplay of multi-level factors suggested by the ecological model (i.e., individuals, interpersonal, environmental). The aim is to make the healthy option the easy option for all to create sustainable change.

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