Twenty-four nursing college students ages 16 to 17 Year were selected as research subjects and divided into two group. Group A comprised 12 individuals who were trained for short distance running (5KM/day) over a five week period, while Group B was trained for middle distance running (7KM/day) during the same period. Breathing frequency, blood pressure, pulse rate and body surface skin temperature were measured at rest (before training) and after exercise every week. Troponin T (TnT). Creatin kinase (CK), Creatine kinase -MB (CK-MB), and Lactate Dehydrogenase (LDH) tests were performed using blood samples and were used as indicators of the impact on heart muscle during exercise. There were no significant differences in breathing frequency, blood pressure, pulse rate or body surface skin temperature between groups A and B before or after training. After one week, the CK levels in both group were higher after exercising than before the training program had begun, and there were significant differences (P < 0.05) between the two groups. Thenceforth, the CK levels in group A decreased to the normal values and stayed the same throughout the fifth week. The CK levels in group B decreased to the normal value after training for three weeks, and there were significant differences between the values before exercising and those for the forth and fifth weeks of training. Although the levels of CK-MB, LDH, and Troponin-T increased after training, all were within the normal range, and no significant difference was observed before or after five weeks of training.(ABSTRACT TRUNCATED AT 250 WORDS)