['Current physical activity guidelines imply that, by comparison with moderate physical activity (MPA), the benefits of engaging in vigorous physical activity (VPA) are attributed to the greater energy expenditure dose per unit of time and do not relate to intensity per se. The purpose of this study was to determine whether VPA influences the metabolic syndrome (MetS) independent of its influence on the energy expenditure dose of moderate-to-vigorous physical activity (MVPA).', 'Participants consisted of 1841 adults from the 2003-06 National Health and Nutrition Examination Survey, a representative cross-sectional study. MPA and VPA were measured objectively over 7 days using Actigraph accelerometers. MetS was determined using an established clinical definition. Associations between physical activity and the MetS were determined using logistic regression and controlled for relevant covariates.', 'Analyses revealed that VPA remained a meaningful predictor of the MetS after controlling for the total energy expenditure dose of MVPA such that the relative odds of the MetS was 0.28 (95% confidence interval 0.17-0.46) in the group with the highest VPA compared with the group with no VPA. VPA had a greater influence on the MetS than an equivalent energy expenditure dose of MPA. For instance, between 0 and 500 MET min/week of MPA the adjusted prevalence of the MetS decreased by 15.5%, whereas between 0 and 500 MET min/week of VPA the prevalence decreased by 37.1%.'] Is vigorous intensity physical activity related to the metabolic syndrome independent of the physical activity dose?