"Background: Physical activity (PA) has benefcial efects on health and health-related quality of life (HRQoL), which
is a protective factor of illness and mortality. The purpose of this examination was to investigate if self-reported and
device-based measures of PA were related to HRQoL in adolescents.
Methods: Participants (N=1565; 54.3% female; Mage=14.37 years, SDage=1.99) were recruited from 167 sample
points across Germany. Adolescents self-reported their PA, supplemented by a 1-week examination of device-based
PA using accelerometry. Additionally, they completed the multidimensional KIDSCREEN-27 to assess HRQoL.
Results: Results showed that self-reported PA was correlated with overall HRQoL, Physical Well-Being, Psychological
Well-Being, Social Support & Peers, and School Environment, whereas device-based PA was only correlated with Physi‑
cal as well as Psychological Well-Being. Further, self-reported PA signifcantly predicted all facets of HRQoL except for
Autonomy and Parent Relations, whereas device-based PA solely heightened the amount of explained variance in the
Physical Well-Being subscale.
Conclusions: Findings demonstrate the importance of self-reported PA as it is related to almost all facets of HRQoL.
Both measures of PA are not congruent in their relationship with HRQoL and thus implications have to be carefully
considered. Future studies should investigate the direct efect of PA on HRQoL and health in a longitudinal approach
to account for the causality of efects."