Systolic is the heart's contraction as it forces blood out to the arteries. Diastolic is the relaxation and filling of the heart's chambers with blood. The wear and tear on your arteries as blood is being forced through causes a breakdown of the inner lining of the arteries. The lower your blood pressure, the less stress on your arteries. Adrenaline is released in the blood stream causing the heart to beat faster.
Proper diet includes low sodium and low fat intakes.
Exercise decreases blood pressure by strengthening the heart muscle, which helps it pump out a greater amount of blood with less effort. Cool down is very important after exercise. It helps the heart return to a resting state, allows blood that has gone to the arms and lets to return to the core of the body, and allows blood pressure to return to normal. Adrenaline and other associated compounds are released during exercise. If exercise is stopped abruptly, these compounds could bombard the heart and cause irregularities in its rhythm.