# The relationship between self-reported and device-based measurements of physical activity and mental distress among adolescents: results from the fit futures study

## TL;DR

This study examines how self-reported and device-based physical activity relates to mental distress in adolescents, finding that social factors like peer acceptance play a key role.

## Contribution

The study compares self-reported and objective physical activity measures in relation to mental distress, highlighting the influence of social factors.

## Key findings

- Self-reported and objectively measured physical activity were cross-sectionally linked to lower mental distress.
- Adjusting for peer acceptance largely removed these associations, suggesting social factors are influential.
- Baseline physical activity was not significantly related to future mental distress after baseline adjustment.

## Abstract

The potential for physical activity to prevent or alleviate mental distress among adolescents is unclear, partially due to a lack of studies using objective measurements of physical activity. The purpose of the present study is to investigate the cross-sectional and longitudinal relationship between self-reported and device-based measurements of physical activity and mental distress among adolescents. A second aim is to explore the degree to which the relationship differs according to physical activity measurement method.

Cross-sectional and longitudinal data from the Norwegian population-based Fit Futures study in 2010-11 and 2012-13 were used. Mean age of the participants was 16.2 years at baseline. Physical activity was measured by self-report and by accelerometer. Mental distress was self-reported. Multiple linear regression analyses were used to analyze the association between physical activity and mental distress, adjusted by demographic, health and life-style variables and peer acceptance.

Using cross-sectional data, self-reported physical activity and objectively measured minutes in moderate to vigorous physical activity were negatively associated with mental distress, up until inclusion of peer acceptance as a covariate in the fully adjusted model. After adjusting for peer acceptance, all but three effects were non-significant. Neither self-reported nor objectively measured physical activity at baseline was significantly related to mental distress at follow-up, after adjusting for baseline mental distress.

Cross-sectionally, both self-reported and objectively measured moderate to vigorous physical activity were significantly related to lower mental distress, but adjusting for peer acceptance rendered the associations mainly non-significant. This finding highlights the important role played by social factors among adolescents, possibly impacting both depressive symptoms and physical activity levels. Physical activity at baseline was not related to mental distress at follow-up, adjusted for baseline mental distress, neither for device-based nor self-reported physical activity.