Background: Research suggests that accumulating moderate to vigorous physical activity (MVPA) in longer continuous bouts may have beneficial effects on metabolic syndrome risk factors. The objective of this study was to examine the independent associations of MVPA bout patterns on metabolic syndrome risk factors among a nationally representative sample of youth. Methods: Results are based on 3165 children and adolescents (6–18 y old) from the 2003–2006 National Health and Nutrition Examination Survey. Accelerometers measured MVPA accumulated in bouts of: <5, 5 to 10, and ≥10 minutes over 7 days. Participants were categorized into quartiles based on percentage of each bout duration. Sensitivity analysis was conducted using 3 versions of MVPA cut points for youth. A series of general linear models were used to compare metabolic syndrome risk factors between groups. Results: Youth participating in longer continuous bouts of MVPA had lower body mass index percentile (P < .02), waist circumference (WC) (P < .01), WC percentile (P < .02), and waist to height ratio (P < .01) than youth participating in shorter bouts of MVPA. When analyzed for interactions between MVPA and bout pattern quartile, only 1 cut point showed a significant interaction for WC and WC percentile. Conclusion: Longer continuous bouts of MVPA had beneficial effects on body anthropometrics and weight status, although these effects may be moderated by total MVPA.