Dr. Andy Galpin

So if I inhibit the inhibitor, I can actually go faster.

So if I remove my foot from that break, my heart rate will increase to, again, somewhere in that 100 to 120 beats per minute range, plus or minus here.

Without us doing anything.

If I want to continue to accelerate past that, so now I'm going down that hill.

I was going 60 miles an hour.

I've removed my foot from the brake.

Now I'm going 80 miles an hour, 100 miles an hour.

But that's not fast enough.

I want to go 150.

Now I can hit the accelerator.

Now I can push down on the sympathetic nervous system, increase adrenaline, turn on a faster rate, and pump my heart even more to produce more work, more energy, or whatever I'm trying to accomplish.

Great.

Now that we've got that down, let's go back and answer our question.

Why doesn't the heart get sore?

Well, let's think about it.

What are the reasons that cause skeletal muscle to get sore?

Remember, all skeletal muscle with the exception of one, and I wonder if you know which one that is, by the way,

All skeletal muscle with the exception of one is connected to bone via tendons.

And so when we contract muscle, it pulls on the connective tissue, pulls on the bone to get you movement.

Our cardiovascular, our heart is not that.