The purpose of this study was to determine and compare blood lactate, heart rate and blood pressure responses in arm and leg exercises and to determine the relationship between these variables and fatigue time during these two modes of exercises. 8 young professional karate players (mean age 18.90±2.20) volunteered to participate in this study. The subjects completed two ergometers: arm and leg ergometers and Monark ergometer (Model 838E). Cardiovascular heart rate (HR), blood pressure (BP) and fatigue time were measured and recorded immediately after each exercise test. Blood samples as well were collected by enzymatic lactate reagent after two exercise tests to measure blood lactate concentrations (mg/dl). There were not significant differences between arm and leg exercises in blood lactate concentration and blood pressure (P=0.22 and P=0.15 respectively). But maximal HR was significantly higher in the leg exercise compared to the arm exercise (P=0.02). The correlations of blood lactate, HR, and BP with fatigue time were r=0.88, r=0.68 and r=0.76 for the arm exercise and r=0.71, r=0.57 and r=0.49 for the leg exercise respectively. The results of this study suggested no significant differences in blood lactate and blood pressure responses between upper and lower body exercises. However, maximal HR response significantly differed between these two exercises. Therefore, when preparing sport exercises, HR responses should be considered separately in arm and leg exercises.