Abstract
INTRODUCTION: The COVID-19 pandemic contributed to an increase of mental health problems like depression, anxiety, stress symptoms, and Internet-based addictive behaviors. Therefore, the present longitudinal study investigated whether physical activity might prevent addictive social media use (SMU) and thus foster positive mental health (PMH) and decrease negative mental health (NMH). METHODS: Data were assessed in a sample of 356 participants (Mage = 27.43, SDage = 6.59) from Germany via online surveys at two measurement time points in spring 2020 (baseline, BL) and one year later in spring 2021 (follow-up, FU). Moderated mediation analyses were conducted for the investigation of the relations. RESULTS: Analyses revealed that addictive SMU (BL) mediated the relationship between physical activity (BL) and PMH (FU) as well as symptoms of depression, anxiety, and stress (FU). Moreover, the association between physical activity and addictive SMU was moderated by the level of burden caused by COVID-19 (BL), i.e., it was significant for medium and high, but not for low burden. LIMITATIONS: The mostly female and relatively young sample limit the generalizability of the current findings. Moreover, the relationships should be investigated in further countries to different time points. CONCLUSIONS: The findings indicate positive effects of physical activity on PMH and NMH by the reduction of tendencies of addictive SMU. Especially people who experience high levels of burden by COVID-19 may benefit from regular physical activity. This could be a cost-effective, low-threshold prevention strategy for meeting the pandemic induced challenges for mental health.