Physical activity behaviours in adolescence: current evidence and opportunities for intervention

Abstract

Young people aged 10-24 years constitute 24% of the world's population; investing in their health could yield a triple benefit-eg, today, into adulthood, and for the next generation. However, in physical activity research, this life stage is poorly understood, with the evidence dominated by research in younger adolescents (aged 10-14 years), school settings, and high-income countries. Globally, 80% of adolescents are insufficiently active, and many adolescents engage in 2 h or more daily recreational screen time. In this Series paper, we present the most up-to-date global evidence on adolescent physical activity and discuss directions for identifying potential solutions to enhance physical activity in the adolescent population. Adolescent physical inactivity probably contributes to key global health problems, including cardiometabolic and mental health disorders, but the evidence is methodologically weak. Evidence-based solutions focus on three key components of the adolescent physical activity system: supportive schools, the social and digital environment, and multipurpose urban environments. Despite an increasing volume of research focused on adolescents, there are still important knowledge gaps, and efforts to improve adolescent physical activity surveillance, research, intervention implementation, and policy development are urgently needed.

Figure 1. Overall physical activity (expressed as total activity counts) from accelerometry in U.S. and European males and females from 10 to 24 years of age.

Note: Data for U.S. males (blue) and females (red) are smoothed 50th percentiles from NHANES 2003-2006. Data for European males (grey) and females (yellow) are age-specific median values from the Determinants of Diet and Physical Activity Knowledge Hub (DEDIPAC). Dotted lines indicate the estimated total activity counts associated with the adolescent guidelines (60 mins/day) and young adult guidelines (150 mins/week). See appendix 1 for methodological details.

Figure 2. Prevalence of watching TV (HBSC, 37 countries); playing computer games (HBSC, 38 countries); recreational sitting (GSHS, 97 countries); and no walking or cycling to or from school (GSHS, 73 countries).

Note: Data shows prevalence with minimum and maximum country values. HSBC data is from 2014, GSHS data from 2003-2017. See Appendix 2 for methodological details.

Figure 3. Effects of interventions to promote physical activity or reduce sedentary behaviour in adolescents (standard mean differences from original systematic reviews).

Note: See Appendix 6 for review methods, detailed results, and references.