Physical activity was associated with differential anxiety trajectory membership among adolescents, but these associations unfolded within a broader pattern of psychosocial stability, with exercise self-efficacy showing a more consistent role than body image and the hypothesized serial indirect pathway not robustly supported.
Key Findings
Results
The majority of adolescents with complete data exhibited stable anxiety patterns across the academic year, with only a minority showing meaningful variability.
Of 1,243 participants with complete data, 76.7% were classified into the stability-dominant subgroup.
23.3% were classified into the variability-dominant subgroup, where trajectory modeling was applied.
Participants were stratified using cross-wave similarity before trajectory estimation.
The study spanned one academic year with three measurement waves.
Results
Within the variability-dominant subgroup, a three-class latent trajectory solution was retained, comprising Stable Elevated, Declining Improvement, and Increasing Risk anxiety trajectories.
The Stable Elevated trajectory comprised 60.0% of the variability-dominant subgroup.
The Declining Improvement trajectory comprised 18.6% of the variability-dominant subgroup.
The Increasing Risk trajectory comprised 21.4% of the variability-dominant subgroup.
Trajectory estimation used latent class trajectory modeling within the variability-dominant subgroup only.
Results
Baseline physical activity was associated with differential anxiety trajectory membership within the variability-dominant subgroup.
Associations were examined using multinomial logistic regression controlling for grade, sex, and age.
Baseline physical activity differentiated subsequent trajectory membership across the three-class solution.
The study was conducted among 1,395 middle school students, with 1,243 providing complete data.
Physical activity was described as more relevant to 'developmental positioning across anxiety trajectories than to a simple uniform symptom-reduction model.'
Results
Baseline physical activity positively predicted later exercise self-efficacy and body image.
Associations were examined using linear regression controlling for grade, sex, and age.
Exercise self-efficacy also positively predicted later body image independently.
These associations were examined across three measurement waves over one academic year.
Physical activity's positive association with exercise self-efficacy was described as more consistent than its association with body image in downstream pathway analyses.
Results
The hypothesized serial indirect pathway from physical activity through exercise self-efficacy and then body image to anxiety trajectory membership was not consistently supported.
Bootstrap-based indirect pathway models were used to test the serial mediation hypothesis.
The serial pathway was 'not consistently supported across trajectory contrasts.'
Exercise self-efficacy showed 'a more consistent role than body image' in associations with trajectory membership.
The authors concluded the serial pathway was 'not robustly supported,' indicating the mediation chain did not hold uniformly across all trajectory group comparisons.
Results
Exercise self-efficacy played a more consistent role than body image in the associations between physical activity and anxiety trajectory membership.
Both exercise self-efficacy and body image were examined as potential intermediary variables using bootstrap-based indirect pathway models.
Exercise self-efficacy was described as showing 'a more consistent role than body image' across trajectory contrasts.
The findings suggest exercise self-efficacy may be a more reliable psychosocial mechanism linking physical activity to anxiety outcomes in adolescents.
These analyses controlled for grade, sex, and age.
What This Means
This research suggests that among middle school students followed over one academic year, most adolescents (about 77%) showed relatively stable anxiety levels, while roughly 23% had meaningfully changing anxiety patterns. Among this changing group, three distinct trajectories emerged: a large group with consistently elevated anxiety, a smaller group whose anxiety improved over time, and another group whose anxiety worsened. Adolescents who were more physically active at the start of the study were more likely to be on different anxiety trajectories compared to less active peers, suggesting physical activity may influence where a young person ends up developmentally rather than simply reducing anxiety symptoms uniformly.
This research also suggests that being physically active was linked to greater confidence in one's ability to exercise (exercise self-efficacy) and a more positive body image, and that exercise self-efficacy was in turn linked to better body image. However, the idea that physical activity improves anxiety specifically by first boosting exercise self-efficacy and then improving body image — a chain of effects — was not consistently confirmed across the different trajectory groups. Exercise self-efficacy appeared to be a more reliable factor in these associations than body image alone.
The practical implication is that encouraging physical activity in adolescents may matter most for shaping long-term anxiety patterns rather than producing immediate, uniform symptom relief. The finding that most students showed stable anxiety regardless of other factors also highlights that anxiety in adolescence is not simply reactive to short-term influences. Supporting young people's confidence in their ability to be physically active may be a meaningful target for programs aimed at adolescent mental health.
Check Your Own Numbers
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Xiong W, Yu J, Zhang Z, Fan Y. (2026). Physical activity and adolescent anxiety trajectories: a longitudinal analysis of exercise self-efficacy and body image.. Frontiers in public health. https://doi.org/10.3389/fpubh.2026.1825516