The relationships of central obesity and physical fitness to indexes of hemostatic, lipid and glucose metabolism both at baseline and after 1 year of diet and exercise intervention were examined in 209 sedentary middle-aged men and women with increased coronary risk factor levels. Central obesity was measured as either waist circumference or waist/hip ratio. Maximal oxygen uptake was used as a measure of physical fitness. The cross-sectional results show that there were significant correlations between waist circumference and euglobuline clot lysis time (r = 0.23), factor VII (r = 0.16), glucose and insulin before and after 1 h glucose load (r ranging from 0.32 to 0.50). The 1-year intervention gave the following associations between changes in waist circumference and changes in: euglobuline clot lysis time (r = 0.27), factor VII (r = 0.19), carbohydrate variables and lipids (magnitude of r ranging from 0.19 to 0.43). Also the other indexes of obesity and physical fitness showed significant correlations to indexes of hemostatic, lipid and glucose variables, both cross-sectionally and for changes after the 1-year intervention. The associations between changes in central obesity and changes in indexes of hemostatic, carbohydrate and lipids were generally stronger during 1 year of diet and exercise intervention than those found at baseline. Multiple regression analyses with waist circumference, waist/hip ratio, percent body fat and Vo2 max as independent variables and indexes of hemostatic, carbohydrate and lipid metabolism as dependent variables showed that waist circumference was a significant predictor for indexes of the hemostatic, carbohydrate and lipid metabolism, mostly independent of physical fitness. The cross-sectional and 1-year change results support each other and therefore underscore the importance of abdominal obesity as an important risk factor for cardiovascular disease.