The present study was designed to investigate the left ventricular function and muscle oxygen delivery in young men and women at peak Wingate anaerobic test. Young healthy men and women underwent the Wingate anaerobic test. Two-dimensional direct M-mode echocardiography studies were performed with the subject seated on a bicycle ergometer. Arterial O2 was defined from echocardiograph and venous oxygen content. At rest, left ventricular mass index, end diastolic dimension, maximal oxygen uptake, stroke volume and cardiac output were all significantly (p < 0.05) higher in men than in women. At peak Wingate anaerobic test, men compared to women had significantly (p < 0.05) higher values of cardiac output (14.4±0.6 and 12±0.3 l min-1, respectively) and stroke volume (78.0±5.0 and 69.0±6.1 ml, respectively), while (a-v)O2 (118.5±2.9 and 98.1±3.1 mlO2, respectively), oxygen uptake (26.3±1.4 and 22.7±1.1 ml kg1 min1, respectively)and %VO2 out of total energy utilized (10.0 and 11.8 %, respectively) were significantly (p < 0.05) lower. This study indicates gender-related differences in left ventricular response and muscle oxygen delivery of young men and women at peak all-out strenuous exercise. Data suggest that healthy women response to the Wingate anaerobic test by increasing their muscle oxygen extraction in the face of lower oxygen delivery.