How Exercise Makes the Heart Stronger

Resting heart rate is usually between 60-80 beats per minute; males tend to have a lower rate than females, and the resting rate tends to fall with age and cardiovascular efficiency. Keeping track of your resting and exercise heart rate over a prolonged period of time, can reveal some interesting things about your progress.

One of the functions of the heart is to deliver oxygenated blood to the working muscles. When you first start an exercise program, your heart has to work a lot harder to keep up with your body's demand for blood and oxygen. After working out on a regular basis, your aerobic system gradually becomes more efficient so your heart doesn't need to work as hard to do the same job. This is largely due to an increase in stroke volume. Stroke volume is the amount of blood pumped out of the heart per beat. An increase in stroke volume allows the heart to beat slower given the same oxygen demands. Both of these factors, an increase in stoke volume and a decrease in heart rate; increase cardiac output, which is an indication of cardiovascular health.