It is significant for whole body training of endurance ability or exerise as rehabilitation treatment of various diseases, that a fixed quantity of exercise in response to a defined level of heart rate could be loaded voluntarily.<BR>In the present studies it was determined heart rate, respiration rate, number of steps, treadmill speed, moreover, relationship between treadmill speed and heart rate, sudden change of exercise strength on intentional fixed quantity exercise in response to previously defined level of heart rate could be loaded by treadmill connected with “Heart Rate Controller (Quinton Co., Ltd.) ”.<BR>A series of patterns in treadmill running of the normal adult males were analyzed.<BR>On the other hand, transition of blood chemical substances during above exercise at defined heart rate were determined by use of the SMAC-System autoanalyzed (Technicon Co., Ltd.) .<BR>The obtained results in the follows;<BR>1) The relation between treadmill speed and heart rate defined at 130 beats/min, 150 or 170 each, are as follows.<BR>a) Treadmill speed at heart rate, previously defined as 130 b/min was 80±5-12 meters/min, actual heart rate during above exercise was 130±3-8 b/min in record.<BR>b) Treadmill speed at heart rate, 150 b/min was 100 ±9-18 m/min, actual heart rate 150±6-8 b/min in record.<BR>c) Treadmill speed at heart rate, 170 b/min was 130±10-33 m/min, actual heart rate 170±3-9 b/min in record.<BR>2) In the present studies respiratory rate during exercise at defined heart rate level neither altered nor had relation with treadmill speed. The number of steps did not alter, rather appeared to determine respiratory rate.<BR>3) When sudden change of exercise strength during exercise at defined heart rate level appeared, for instances, treadmill speed got quicker, deviated raise of rate from defined heart rate level varied by the individuals and also load on heart itself did by the individuals.<BR>4) In determination of blood chemical substances during exercise at defined 150 b/min or 170 b/min of heart rate level by SMAC-System, transition of above substances were observed to be within normal range but thier levels before exercise were promptly restored.<BR>From the results mentioned above it is suggested that process of intermediated metabolism during above exercise could be considerably stable and exercise load at a defined heart rate level can be prescribed intentionally.