Adamčák, ŠtefanMarko, MichalKľocová Adamčáková, Zora2026-06-012026-06-0120262673-7051https://doi.org/10.3390/adolescents6020034https://repo.umb.sk/handle/123456789/1486In: Adolescents. Basel : Multidisciplinary Digital Publishing Institute, 2026. ISSN 2673-7051. Vol. 6, no. 2 (2026), pp. [1-17].This study aims to provide insights into how physical activity is associated with sleep patterns in youth populations, in particular, Slovak adolescents, and how gender (boys vs. girls) and age (≤16 vs. ≥18) moderate this relationship, using an extreme-group comparison approach that excludes 17-year-olds to enhance contrast between developmental stages. Using a cross-sectional design, self-reported data were collected from 2504 (100%) high school students (aged 15–19; 45.6% boys, 54.4% girls) using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and the Pittsburgh Sleep Quality Index (PSQI). Participants aged 17 years were excluded from age-stratified analysis to create clearer separation between early/mid and late adolescence. The primary outcome was global sleep quality (PSQI > 5). Secondary outcomes included sleep duration and PSQI component scores. All other analyses (age- and gender-stratified comparisons and interaction models) were predefined as exploratory and hypothesis-generating to examine potential effect modification. Age-stratified analyses among girls showed that, within the low PA group, good sleep was reported by 37.7% of younger girls (≤16) and 28.6% of older girls (≥18). Among older girls, the proportion reporting good sleep increased to 49.8% in the high PA group (χ2 = 29.16, p < 0.001). No consistent associations between PA and sleep quality were observed among boys; however, significant association was identified among younger boys (≤16 years), which was not observed in older boys. Logistic regression revealed a modest interaction between age and PA level in predicting sleep quality among girls (β = 0.346, p = 0.049), suggesting small age-dependent variation in the association. This effect should be interpreted cautiously given its borderline statistical significance. Component-level PSQI analyses showed that girls experienced higher rates of sleep disturbances (χ2 = 91.40, p < 0.001), longer sleep latency (χ2 = 26.71, p < 0.001), and greater daytime dysfunction (χ2 = 79.90, p < 0.001). These findings provide region-specific evidence from Central and Eastern Europe and underscore the need for age- and gender-sensitive public health strategies targeting both physical activity promotion and better sleep outcomes, given their observed associations.enCC BY Creative Commons Attribution 4.0. Internationalinfo:eu-repo/semantics/openAccessadolescentidospievajúca mládežadolescentsrodové rozdielygender differencesfyzické aktivitykvalita spánkusleep qualityArticle