Normal subjects of both sexes between 20 and 63 years were examined with M-mode echocardiography. Blood pressure (BP), heart rate (HR), and left ventricular (LV) diastolic and systolic function were measured at rest and at the end of a standardized maximal isometric handgrip test. BP and HR increased about 25%. This increase in cardiac work had no significant influence on LV systolic function. Diastolic function (myocardial relaxation and maximum rate of LV filling), however, improved significantly. Isometric handgrip test is a suitable exercise test in combination with M-mode echocardiography. Studies on LV function during exercise may improve the sensitivity for detection of mild LV dysfunction.