Four in five adolescents worldwide do not get enough physical activity, to the detriment of their health, the World Health Organization said Friday, warning that girls especially need more exercise.
In its first ever report on global trends for adolescent physical activity, the UN health agency stressed that urgent action was needed to get teens off their screens and moving more.
“We absolutely need to do more or we will be looking at a very bleak health picture for these adolescents,” study co-author Leanne Riley told journalists ahead of the launch.
The report, which was published in the Lancet Child & Adolescent Health journal, is based on data from surveys conducted between 2001 and 2016 of some 1.6 million students between the ages of 11 and 17 across 146 countries.
It found that 81 percent did not meet the WHO recommendation of at least an hour a day of physical activity such as walking, playing, riding a bike or taking part in organised sports.
This is worrying, since regular physical activity provides a host of health benefits, from improved heart and respiratory fitness to better cognitive function, making learning easier.
Exercise is also seen as an important tool in efforts to stem the global obesity epidemic.
But despite ambitious global targets for increasing physical activity, the study found virtually no change over the 15-year-period it covered.
“We are not seeing any improvements,” Riley said.
While the report does not specifically study the reasons for adolescent physical inactivity, she suggested that the “electronic revolution… seems to have changed adolescents’ movement patterns and encourages them to sit more, to be less active.”
The report authors also pointed to poor infrastructure and insecurity making it difficult for adolescents to walk or bike to school.
The study found that levels of physical inactivity among adolescents were persistently high across all regions and all countries, ranging from 66 percent in Bangladesh to 94 percent in South Korea.
“We find a high prevalence pretty much everywhere,” lead author Regina Guthold told journalists, noting that in “many, many countries, between 80 and 90% of adolescents (are) not meeting the recommendations for physical activity.”
Girls less active
And the situation was particularly concerning for adolescent girls, with only 15 percent of them worldwide getting the prescribed amount of physical activity, compared to 22 percent for boys.
In fact, girls were less active than boys in all but four countries—Afghanistan, Samoa, Tonga and Zambia.
And while the situation for boys improved somewhat between 2001 and 2016, with inactivity levels dropping from 80 to 78 percent, girls remained at 85 percent.
In a number of countries, the gender gap appeared to be linked to cultural pressure on girls to stay home and shun sports, as well as concerns over safety when moving about outdoors.
But Guthold also pointed out that “a lot of physical activity promotion is more tailored towards boys.”
This, she said, seems to explain the fact that the biggest gender gap could be found in the United States and Ireland, where the difference in activity levels between boys and girls was over 15 percentage points.
“In the United States, we see that since 2001, levels of insufficient activity have decreased in boys by seven percent, while there has been no change in girls,” she said.
The US for instance put in place an ambitious national plan for physical activity in 2010, but the efforts “for some reason only seem to reach boys.”
In a bid to encourage healthier living, countries have set a target of reducing physical inactivity among adults and youth alike by 15 percent between 2018 and 2030.
But Riley noted that meeting that target would be a challenge after driving down adolescent inactivity by a mere percentage point over the past 15 years.
“We need to do more if we want to halt the rise in obesity in this age group and promote better levels of physical activity,” she said.
Even though physical activity (PA) has been identified as the ‘best buy’ in public health  and national actions for the promotion of PA have been employed in many countries , population levels of PA are still declining [2–4]. In contrast, time spent performing sedentary behaviour (SB) is increasing [3, 4]. SB refers to any waking activity in a sitting, reclining, or lying position with low energy expenditure . In the academic literature, SB has been conceptualised in two ways: (i) as a health risk factor ‘independent’ of PA ; and (ii) as a part of the time-use composition consisting of sleep, SB, and PA co-dependent time-use components . In both conceptualisations, SB is deemed a potentially important factor for population health. Nevertheless, there seem to be barriers to the promotion of PA and reduction of SB, especially in low- and middle-income countries. These barriers include workforce shortages in the PA/SB sector (e.g. lack of PA promoters), weak networks of collaboration with other sectors (e.g. education, sports, and transportation), the lack of effective actions, and lack of knowledge about what approaches to PA promotion and SB reduction are feasible [2, 8]. These have been major challenges in Thailand, where efforts have been made to design and implement policy-level interventions.
To develop effective programs or interventions to increase PA and reduce SB, there is a need to understand correlates of these behaviours in specific populations. Public health experts advise that this need is urgent in low- and middle-income countries [2, 9]. Moreover, given substantial differences between geographical areas in social, cultural, environmental, and economic factors, it is important to explore PA and SB correlates in specific countries so that feasible interventions can be developed and designed based on local data . Studies on PA correlates in low- and middle-income countries have recently started receiving more attention [2, 9–13]. Since 1987, and especially over the last two decades, PA has been the focus of a plethora of Thai epidemiological research, and the attention has most commonly been placed on its correlates .
In Thailand, the data from a 2015 population-representative survey on PA and SB showed that 21-25% of Thai children and adolescents (aged 6–17 years) achieved the recommended level of PA (i.e. 60 minutes a day) . In addition, more than 78% of Thai children and adolescents engaged in two or more hours of SB . Around 40% of Thai adults (aged 18 and above) met the World Health Organisation (WHO) recommendations for moderate-to-vigorous PA (MVPA) [16, 17]. Interestingly, 33.8% of Thai adults reported a high level of SB and no MVPA in the past week . A better understanding of what makes some Thai population groups less active than others may help tackle the problem of insufficient PA.
Like other healthy behaviours, PA and SB are influenced by many factors [9, 18–22]. However, the focus to date has mostly been on individual-level correlates, such as sex, age, attitude, and self-rated general health [9, 11, 14, 20–22]. The social-ecological approach has been widely adopted to understand the interrelationships among multiple factors that contribute to PA and SB, including individual, social, environmental, and policy factors [9, 18–22]. The full spectrum of PA/SB correlates has been analysed in several reviews, mostly in high-income countries such as the United States, Australia, and Canada [9, 20–25]. Studies from low- and middle-income countries including Thailand have rarely been included [9, 20–25].
Given the importance of knowing which variables are associated with PA and SB in a specific population, the aim of this study was to systematically review and summarise the available evidence on individual, social, environmental, and policy correlates of PA and SB in Thai children, adolescents, adults, and older adults. We also aimed to identify the key gaps in the literature on PA and SB correlates in Thailand and provide recommendations for future research.
This review is one of the first to summarise within-country correlates of PA and SB across population groups. Given a range of differences between the findings of the current review and the findings of previous non-country specific reviews, it may be important to consider correlates of PA and SB at the country-level. This may be particularly relevant when such reviews are completed to inform national- and local-level public health interventions.
Findings of the current review suggest that several factors are associated with PA levels in the Thai population. Based on the available evidence, to increase PA in Thailand, public health interventions should focus on helping individuals: improve self-efficacy; circumvent perceived barriers for PA; improve general and mental health; find enough spare time to engage in PA; improve physical skills, abilities, and fitness; gain knowledge about and experience in exercise; and receive adequate social support for participation in PA. Furthermore, the body of literature on correlates of SB in Thailand is limited. Nevertheless, evidence suggests that interventions for reducing SB in Thai adults should primarily target obese individuals, as they seem to be at a greater risk of high SB.
More Thai studies are needed on PA correlates, particularly among children and adolescent and with a focus on environment- and policy-related factors. Much greater commitment is needed to investigating correlates of SB in Thailand, particularly among older adults. The Thai Government and public health stakeholders should provide a systematic support to such research, as it provides knowledge that is crucial for designing public health policies, strategies, and interventions.