 This study found that adherents to World Health Organization, WHO, guidelines for physical activity, PA, and screen time, ST, during the COVID-19 pandemic was associated with lower health-related quality of life, HRQL, among primary and secondary school students in Switzerland. The authors observed a decrease in adherents to PA and ST recommendations in 2020, which returned to pre-pandemic levels by 2022. Additionally, fewer children met ST recommendations in 2020 and 2021 compared to before the pandemic, while adherents to PA recommendations remained relatively stable. Finally, the authors found that children who met both PA and ST recommendations had significantly better HRQL than those who did not meet any or both recommendations. This article was authored by Sarah, our highly Samuel Guns, Gabriella P. Peralta, and others.