Global Accelerometer-derived Physical Activity Levels from Preschoolers to Adolescents: A Multilevel Meta-analysis and Meta-regression.

BACKGROUND

Global level physical activity surveillance studies were primarily based on self-report data that could generate inaccurate results.

PURPOSE

To investigate global accelerometer-measured daily moderate to vigorous physical activity (MVPA) changes from preschool age to adolescence as well as gender differences in MVPA while adjusting for the geographic regions and major MVPA cut points.

METHODS

A comprehensive search was conducted through August 2020 that includes 30 databases such as Academic Search Ultimate, Child Development & Adolescent Studies, Education Full Text, ERIC, General Science, PsycINFO, ScienceDirect, and SPORTDiscuss. We included both cross-sectional and longitudinal MVPA tracking studies with daily MVPA being measured by waist-worn accelerometers and determined by either Freedson 3 METs, 4 METs, or Evenson cut points for preschoolers, children, and adolescents.

RESULTS

Researchers analyzed 84 studies reporting on 124 effect sizes with a total of 57,587 participants. The combined data showed significant MVPA differences among various continents of participants (p < .001) or cut points (p < .05-.001) for both preschoolers, children, and adolescents. Globally, when continents and cut points were controlled, individuals' daily MVPA time decreased every year by an average of 7.88, 10.37, and 6.68 min from preschool age to adolescence, preschool age to children, and children to adolescence, respectively. When cut points and continents were controlled, boys had significantly higher daily MVPA than girls for all three age groups (p < .001).

CONCLUSIONS

Globally, individuals' daily MVPA starts to decline dramatically as early as the beginning of preschool age. Early intervention is needed to counteract the high decline rate in MVPA.