Sedentary lifestyle, poor cardiorespiratory fitness, and the metabolic syndrome

Purpose: The cross-sectional associations of leisure-time physical activity (LTPA) and cardiorespiratory fitness with the metabolic syndrome (MS) were investigated in a population-based sample of 1069 middle-aged men without diabetes, cardiovascular disease, or cancer. Methods: LTPA was assessed using a detailed quantitative questionnaire. Maximal oxygen uptake (<(V)over dot>O-2max) and core and related features of the MS were determined. A modified World Health Organization definition of the MS and factor analysis were used. Results: Men who engaged in at least moderate-intensity (greater than or equal to4.5 metabolic equivalents) LTPA < 1.0 h(.)wk(-1) were 60% more likely to have the MS than those engaging in greater than or equal to 3.0 h(.)wk(-1) even after adjustment for confounders. Low-intensity (<4.5 metabolic equivalents) LTPA was not associated with the metabolic syndrome. Men with a <(V)over dot>O-2max <29.1 mL(.)kg(-1.)min(-1) were almost seven times more likely to have the MS than those with a <(V)over dot>O-2max greater than or equal to35.5 mL(.)kg(-1.)min(-1) even after adjusting for confounders. In first-order factor analysis using a promax rotation, the principal factor explained 20% of total variance and had heavy loadings for <(V)over dot>O-2max (-0.57) and at least moderate-intensity LTPA (-0.44), and moderate or heavy loadings for the main components of the MS. The second-order factor analysis generated a principal factor that was strongly loaded on by the main components of the MS and <(V)over dot>O-2max (-0.50) but not LTPA. Conclusion: A sedentary lifestyle and especially poor cardiorespiratory fitness are not only associated with the MS but could also be considered features of the MS. Measurement of <(V)over dot>O-2max in sedentary men with risk factors may provide an efficient means for targeting individuals who would benefit from interventions to prevent the MS and its consequences.