The aim of the present study was to elucidate the effects of 4 different cardiovascular drugs on blood lactate levels during an intensive graded exercise test in 17 healthy male subjects. In acute studies, isosorbide dinitrate and nifedipine were used. In chronic studies, propranolol dihydrochloride and dilazep dihydrochloride were used. Oxygen uptake (VO2), heart rate, blood pressure and blood lactate were measured at rest and during the final minute of each exercise session. Hemodynamic measurements during submaximum exercise were influenced by all drugs except isosorbide dinitrate. VO2 during submaximum and maximum exercises remained unchanged by all drug treatments. Blood lactate levels at rest and during submaximum and maximum exercise also did not change significantly. Work load corresponding to blood lactate concentration of 4 mM (W4 mM) and the 1st and 2nd break points of lactic acid (WBPLA1 and WBPLA2) were almost the same in all treatments. It is concluded that the 3 criteria of blood lactate obtained during the graded exercise test are not affected by these drugs in healthy males.