Aim: To determine the influence of isometric muscle contraction on blood pressure. Methods: Morphologic characteristics were analyzed using bioelectric impedance method on GAIA 359 + apparatus. Blood pressure was measured with Marshall MB85. Values of systolic and diastolic blood pressure, as well as heart rate during contractions of different muscle groups were compared to the values in resting using paired t-test, and changes that have occured during contractions of different musle groups were compared using unpaired t-test. Correlation between morphologic characteristics and changes in heart rate and blood pressure was determined with Pearsons correlation. Statistical significance was determined at p=0.05. Results: This research was conducted on 7 male examinees, age 22±2. Results point out to significant increasment of heart rate, as well as blood pressure during contraction of lower extremities (median heart rate (MR) 29,57; p=0,001; systolic blood pressure (MR) 13,28; p=0,04; diastolic blood pressure (MR) 15,14; p=0,001) and muscles of the torso (heart rate (MR) 33,71; p=0,004; systolic blood pressure (MR) 11,14; p=0,05; diastolic blood pressure (MR) 20,42; p=0,004). There is no statistical significance in rest of the measured muscle contractions, as well as in correlation between morphological characteristics, heart rate and blood pressure. Conclusion: Blood pressure and heart rate increased due to isometric muscle contraction. To determine the difference between increasement of heart rate and blood pressure among different muscle groups using isometric contraction, as well as, correlation between these changes and morphologic characteristics larger number of examinees is needed.