Dr. Andy Galpin

It's your arms, legs, neck, shoulders, things like that.

And then cardiac muscle, your heart.

And you know when you exercise really hard or do something unique and novel, train over a larger range of motion, do more eccentric work and all these other things, your muscles get sore.

But why does your heart ever get sore?

If you went out right now and you haven't exercised in years and you ran a VO2 max test, you would get extremely tired, but you would not wake up the next day with a sore heart.

Your intercostals or your ribs or your low back or something might be sore, but not your heart.

Well, why is that?

Well, actually, the answer to that tells us a lot about how we should assess the functionality of our cardiovascular system, as well as how we need to think about training it differently than we train skeletal muscle.

You see, it always comes back to physiology, right?

So there's a reason we're going to walk you through how the heart is set up, the structure of the fibers, why it contracts the way it does, because again, this gives us insights into why we need to totally change our mindset about how we're going to train and improve it

relative to how we talked about and we'll talk about training our skeletal muscle.

So the heart is made up of really four unique areas and we call these chambers.

There's got two at the top called your atria, your left and right, and two at the bottom called your ventricles.

And really the idea is you take blood from the atria, you squeeze and contract the atria, that pushes blood into the ventricles.

The ventricles then squeeze and that pushes blood out of your heart and into your system.

There's a lot more detail in there, but that's close enough for now.

Of primary interest is the left ventricle.

That's actually the reason why when you see a heart, it isn't that perfect, unique, symmetrical shape that you envision when your five-year-old daughter draws it.

It's actually slightly tilted to the left a little bit.

And that's because the left ventricle itself is larger than the right ventricle, primarily because the right ventricle just needs to pump blood to the other side of the heart,