The metabolic syndrome may lead to cardiovascular disease. A greater number of physical activities and better fitness decrease the prevalence and incidence of metabolic syndrome. Exercise increases insulin sensitivity and longer activities make the effect greater. Studies have shown that physical activity is also helpful in treating the metabolic syndrome. Moderate aerobic physical activity for more than 30 minutes almost every day (at least 5 or more days a week) is recommended to prevent and treat the metabolic syndrome. Moderate aerobic physical activity for more than 150 minutes total per week with intermittent resting days may be effective in managing the metabolic syndrome. Intermittent activity for periods of at least 10 minutes has been shown to be as effective as continuous activity. Examples of moderate activities are walking, brisk walking, table tennis, vacuuming, and playing drums. For a more accurate exercise prescription, a target heart rate can be used, calculated by the formula: 'target heart rate = intensity × (maximal heart rate - resting heart rate) + resting heart rate'. The intensity for moderate physical activities is 40% to 50%. Maximal heart rate is assumed to be '220-age'. Resistance exercise two or three times a week per muscle group is also recommended. Reducing sedentary life habits such as watching TV, playing video games, and working on a computer is recommended, too. The more physical activities in everyday life, the better the results for the metabolic syndrome. However, the exact amount of physical activity for the metabolic syndrome should be determined by further studies in Korea. Physical activity is an essential tool in the prevention and treatment of the metabolic syndrome.