Rhonda Patrick, Ph.D.

And what shear stress is, is essentially just the friction of the blood flow against this interior lining of the arteries and the vascular system, right?

There's a friction there.

And so the stronger...

The exercise, the more vigorous the exercise, the faster your heart is pumping.

And that's why heart rate does come into this.

The more your blood flow is moving, right?

So you're getting a stronger, sheer stress.

And that is actually not a bad type of stress.

It's a good type of stress.

The sheer stress causes your endothelial cells lining your arteries to adapt automatically.

And in a way where it improves vascular function, it improves endothelial function, and it causes these endothelial cells to secrete beneficial molecules.

So one of those would be nitric oxide.

Many people have heard of that.

And the other one would be prostacyclin.

And both of these compounds are causing vasodilation, you know, they're improving blood flow.

But over time, and as you continue to repeat this sheer stress, what happens is you're improving the flexibility of your arteries, you're making them more resilient, they're able to handle stress better, you're improving their overall functioning, and you're making them more resilient and resistant to

atherosclerosis, right?

And that is essentially, I think, at the crux of what's going on here with respect to why vigorous intensity exercise is so beneficial for cardiovascular health.

We know Dr. Levine has come on the podcast and talked about, you know, some of the benefits of doing more vigorous intensity exercise and how you get more stronger cardiovascular adaptations.

And if we look at even that study he did in middle-aged adults,