Activities in previous year, 50 adolescents (42%) had pari in leisure activities and 15 (12,6%) in school activities. parisc led to an average of 10 missed days from school or leisure-time activities. parilt led to 7,2 missed days and paris led to 6,2 missed days. spearman’s correlations (n = 50 for parisc and n = 119 for parilt and paris) revealed associations between mai and parisc, parilt and paris, but not between mvpa or 20-metre shuttle run laps and parisc, parilt and paris. not surprisingly, percentage of body fat was negatively associated with the number of 20-metre shuttle run laps. in addition, results of crude linear regression models showed that frequency of mvpa was not associated with frequencies of parisc (b coefficients (b)/95% ci: 0,03/-0,11-0,18), parilt (b/95% ci: 0,04/-0,05-0,13) or paris (b/95% ci: -0,02/-0,07- 0,02) among slovak adolescents in our pilot study. conclusions estimating the burden of pari is important in advocating the need of directing sufficient resources to pari prevention along with the pa promotion. improvement and under- standing of factors associated with pari might be helpful in pari prevention. in addition, it might, among other to estimate the associations between change in physical activity patterns and mental health outcomes. results in total, 585 boys (45%) and girls (55%), aged 13-14 years (baseline) from 34 schools around stockholm, were included in the study. between 2019-2021 there was a decrease in hrqol (p > 0.001) and increase in psychosomatic problems (p > 0.001) among both boys and girls. there was a significant positive relationship between change in mvpa and change in hrqol ( b = 0.02, ci: 0.00, 0.05). the results suggest that the covid-19 pandemic has impaired the mental health of swedish adolescents but increased physical activity was related to positive changes in the mental health outcome hrqol