How does exercise change your heart?

We all know that exercise is “good for your heart”, but how does it work? How does your heart adapt through exercise?

The heart is just like any muscle, it can be trained to be “stronger”.


The Graph shows data collected by Dr. Norman Gledhill (an expert in exercise) over a 15 year period. Stroke volume (red) refers to how much blood your heart can “squeeze out” every time it beats. The stronger your heart, the stronger the “squeeze” and the more blood you can pump. Cardiac output (black) refers to the total volume of blood thats pumped per minute. It can be calculated by multiplying your stroke volume by heart rate.

As you can see from the graph, exercise training can drastically improve cardiac output. It is also clear from the graph that the main mechanism of improvement is stroke volume, not heart rate (max HR potential does not change with exercise). So, the next time you are exercising, you now know what with every beat, you’re heart is getting stronger and with that extra strength, you will be able to pump more blood.