Relationships of Social Support, Motivation, and Self-Efficacy With Physical Activity Among Adolescents Aged 10-14: A Cross-Sectional Study.

This cross-sectional study involved secondary data analysis to: (1) examine relationships between psychosocial factors (autonomous motivation for physical activity [PA], PA self-efficacy, social support for PA) and various levels of PA intensity (light PA [LPA], moderate PA [MPA], vigorous PA [VPA]), and moderate-to-vigorous PA [MVPA]) in adolescents aged 10-14 years in the U.S.; and (2) investigate the influence of demographic, physiological, and activity-related characteristics (age, sex, race/ethnicity, body mass index [BMI], annual family income, cardiorespiratory fitness [CRF; estimated maximal oxygen uptake: VO2 max], current sports or cheerleading team participation, and non-sport PA program participation) on various PA intensities. In 2022-2024, adolescents completed demographic and psychosocial surveys and wore accelerometers to assess PA. Of 935 adolescents enrolled, 623 (66.6%) provided valid accelerometer data (≥4 days). Structural equation modeling was used. MPA, VPA, and MVPA were positively associated with male sex, higher CRF, and sports or cheerleading team participation. Age and BMI z-score were negative predictors of MVPA and VPA. MPA was negatively associated with age, and LPA was negatively associated with annual family income. Social support for PA predicted autonomous motivation for PA and PA self-efficacy. Indirect effects of social support on the various levels of PA intensity via autonomous motivation or PA self-efficacy were not significant. Strengthening social support for PA may enhance adolescents' autonomous motivation for PA and PA self-efficacy to help them increase PA. However, indirect effects on the PA levels were not statistically significant. Findings underscore the promise and limitations of psychosocial pathways.ClinicalTrials.gov Identifier NCT04213014.