Internal Combustion. It only takes a few short weeks without exercise for the body to begin its detraining transformation. This is the part of the article that is intended to scare your butt back into the gym - kind of like those anti-tobacco campaigns. Healthy blood pressure readings are vital to your health. That being said, blood pressure numbers are lower on days when you exercise than on those you do not. Think of your arteries and veins as canals that import and export vital goods, via your blood, to the biggest clients in your body, i.e., the brain, heart and lungs. When the canals get congested, it restricts the open seas, resulting in your valuable goods not reaching the ports as efficiently and effectively. When the heart has to work harder due to constricted vasculatures, your blood pressure increases. However, once back into a regular workout routine, these stiffened structures gain flexibility and cause the heart to have a less stressful workload.