warming up is beginnig activity in exercise to prepare body physiologically and psychologically to do more heavy activity and reduse flawed risk before doing exercise or competition. Reseacrh designed is "the randomized pretest-posttest control group design". The samples of this research are eighteen students of 21-23 years old. The students are divided into two groups. Nine students are in active warming up group (G1) and nine students are in passive warming up group (G2). After warming up each group was given sub-maximal physical activity by paddling ergocycle by 80% HRmax. The measurement of blood glucose and lactic acid was done four times: Pre-test, immediately after warming up, 5 minutes and 30 minutes after sub-maximal physical activity. The result of the blood glucose showed (mg/dL); G1: 99,66±2,73 ; 96,66±2,64 ; 92,55±2,18 ; 89,88±3,44. G2: 96,88±3,01 ; 99,22±2,22 ; 93,55±3,24 ; 91,11±5,55. The blood lactic acid (mmol/dL); G1: 2,78±0,41 ; 7,41±1,41 ; 8,82±1,50 ; 3,40±0,49. G2: 1,33±0,41 ; 2,07±0,65 ; 6,30±1,39 ; 3,10±0,66. There is no difference between G1 to G2 to changes in blood glucose, only an increase in blood glucose after passive warming up (p<0,001). Increased in blood lactate after warming up in group G1 is greater than G2 (p<0,001). The conclusions of this study showed that there was an increase blood glucose after passive warming up (G2), decreased in blood glucose after sub-maximal physical activity in both groups and increased in blood lactate after sub-maximal physical activity in both groups
