In the heart. The frequency of contractions of the heart increases to provide the necessary circulation of blood. In men who is more than 40 years, and not engaged in sports, the pulse rate at rest is about 70 beats per minute. With an average load, it can be doubled, and while increasing the load it can reach 180. In average, men in the state of rest the heart pumps about 75 ml of blood per contraction. Exercise may increase this amount by more than 50%. Minute volume of blood pumped in a state of rest equal to about 5 liters of blood (70 strokes, multiplied by 75 ml), may during exercise increased fourfold. The blood pressure. When measuring blood pressure are controlled by two phases: systole - the maximum pressure developed while reducing the heart, and diastolic - the minimum pressure when the heart is relaxed between contractions. Level equal to 120/80 mm Hg, respectively. Art. shall be deemed accepted normal values, but the pressure does not remain unchanged, since the man has no absolutely fixed frequency of contractions of the heart and respiration. Therefore, acceptable values are systolic blood pressure between 100-140 and 60-90 diastolic.
When you exercise systolic blood pressure increases to 180-190, but the diastolic (pulse) pressure should not be changed. His increasing load is a sign of heart disease: this means that the heart is unable to properly respond to it. When doctors removed the electrocardiogram (ECG) under load, then increasing the diastolic pressure - but not very electrocardiogram abnormalities - may be the first signal of cardiac weakness. When deviations in the ECG exercise is vital, because strengthen the heart - the most important muscle. But in this case should be closely monitored by doctors.