Exercise is a fantastic medicine for the body, especially for your heart. When you engage in aerobic training, your cardiovascular system becomes fit. Consistent aerobic activity produces physical changes in the heart, the blood vessels, and in your ability to use oxygen. It’s like getting a complete overall to a car’s engine! Just look at all of the changes:
Resting heart rate is lower after aerobic training. The lowering of the heart rate is due to two primary factors:
The parasympathetic nervous system becomes more dominant at rest, producing a slower resting heart rate. Also, your heart rate returns to its resting rate more quickly after a workout.
The size of the heart chamber grows, meaning it takes fewer heart beats to pump the same amount of blood.
Blood pressure decreases. Exercise, especially moderate aerobic exercise, can lower resting blood pressure in people with high blood pressure. In some cases, it may lower blood pressure as much as 10 mmHg!
Stroke volume increases. Long-term aerobic training helps enlarge the ventricles and strengthens the heart muscle. Because a stronger heart muscle can pump out more blood, these changes result in a larger volume of blood pumped with each stroke. At submaximal work rates, the heart rate is lower because fewer beats are needed to produce the same cardiac output.
Peak cardiac output increases. Cardiac output represents total blood flow through the heart each minute. If you can pump more blood, you can work harder! Because stroke volume is higher, your maximal work output will be greater.
More blood vessels form. The density of capillaries in the muscles increases, meaning more oxygen can be delivered to the muscle. Just as laying more water lines can improve irrigation of a farm field, aerobic training can an increase the “irrigation” of the muscle. In addition, blood vessels that were previously dormant begin to open and move blood.
You’re better able to tap into and use more of the oxygen carried in the blood. This improvement is due to the increase in the size and number of mitochondria (and the enzymes contained within), which draw oxygen from the blood, and to the increased availability of the oxygen as a result of the many blood vessels.
All these changes happen at the same time, which no single medication can achieve. Exercise is the best medicine for changing your body to become fit and to be able to do more work!
