Physical Activity and the Metabolic Syndrome: A Review of the Evidence

Metabolic syndrome is a global public health problem identified as a seminal cause of cardiovascular disease and type 2 diabetes. The syndrome is characterized by the clustering of cardiovascular risk factors, including insulin resistance, central obesity, hypertension, and atherogenic dyslipidemia. Currently there are 5 working medical society definitions of metabolic syndrome. However, the majority of recent research focusing on metabolic syndrome has relied on the National Cholesterol Education Program (NCEP) definition because of its clinical utility. Studies of the association between physical activity and prevalence of metabolic syndrome using National Health And Nutrition Examination Survey (NHANES) data generally found the association to be reduced or attenuated by other lifestyle factors and is generally weaker in females. Other studies tracking physical activity over longer periods have generally found a stronger association between regular physical activity and lower prevalence or incidence of metabolic syndrome. Interventional studies are limited but suggest that regular exercise reduces the incidence of metabolic syndrome. The amount and intensity of physical activity required to prevent or reverse metabolic syndrome has yet to be definitely determined. Evidence suggests that regular, moderate-intensity physical activity may be preventive of metabolic syndrome and that activity of greater intensity may carry greater benefit. Greater cardiorespiratory fitness has demonstrated an even stronger negative association with metabolic syndrome. Strength training is recommended as an adjunct to regular aerobic exercise but is not the primary form of activity to prevent or manage metabolic syndrome.