Multidimensional Physical Activity Phenotypes and Metabolic Syndrome in Korean Adults: A Cross-Sectional Analysis of the KNHANES 2020－2024

Objective: This study compared multiple physical activity indicators (aerobic, resistance, walking, sitting time, and total volume) with metabolic syndrome and its five components in Korean adults.Design: A cross-sectional study using a complex survey design.Methods: Data from 27,254 adults aged ≥9 years were pooled from the Korea National Health and Nutrition Examination Survey (2020-2024).Metabolic syndrome (the pre-specified primary outcome; its five components, secondary outcomes) followed the revised NCEP ATP III criteria with Korean waist cutoffs.Design-based logistic regression estimated odds ratios (ORs) adjusted for sociodemographic and lifestyle covariates, with a mutually adjusted model and Benjamini-Hochberg correction.Results: The weighted prevalence was 35.2%.Aerobic activity (OR 0.86), resistance exercise (OR 0.62), and walking (OR 0.89) showed lower odds, whereas sitting time showed higher odds per 2-hour increment (OR 1.08).When mutually adjusted, only resistance exercise (OR 0.63) and sitting time (OR 1.07) remained independent.Odds fell in a graded manner with greater total activity (highly active OR 0.73, p for trend ＜0.001).Resistance exercise was the only indicator inversely associated with all five components.Conclusions: Physical activity was inversely associated with metabolic syndrome and sitting time positively.These observational findings support combining aerobic and resistance exercise with reduced sitting, although causality cannot be inferred.