So let's talk about endurance exercise and your heart, okay? There's a really good

book. If you do endurance exercise, you need to get this book. It's called The Haywire

Heart, how too much exercise can kill you and what you can do to protect your heart.

By Chris Case in John Mandroa, one-third of marathoners experience dilated ventricles,

okay? So you have, the heart is four chambers. There's two primer pumps, they're called

atrium. Then you have two major pumps, which are ventricles. So what happens with athletes

is they start to develop dilated ventricles, where in large ventricles and one side,

it starts getting bigger. There are indications of heart muscle damage and cardiac fibrosis

that scar tissue within the heart. And that can develop in all sorts of problems with the heart.

One would be ventricular tachycardia, which is one type of arrhythmia. It's kind of a short

circuiting. What the authors talk about in this book is mainly doing exercise for over one hour

every day, sustained endurance exercise, five days a week, week after week after week.

What happens is it creates structural and functional changes within the heart. Now because

the heart is becoming stronger and more efficient, and it pumps out more work and oxygen,

the heart rate comes down. And that heart rate can come down from a normal heart rate, which is

like 72 to 60 to 50 to 40 to sometimes even 30, because the heart doesn't have to work that

hard, everything is very, very slow. And that's healthy, right? Well, what happens is you also

get cardiometalline. So the actual size of the heart can get bigger. One side of the heart can

become bigger than the other side, depending on certain variables. And the name for something

getting bigger is called hypertrophy. The problem is having an imbalance from the left side and

the right side. Because the heart has various things in it that create rhythm, they call pacemakers.

You have two primary pacemakers, but you also have a backup system and even another backup system.

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