Brady Holmer

And it's not just a simple dose response.

It's just not like an area under the curve, I guess, type of thing.

It's you can't just do more low intensity because you're not getting the, it's the intensity of the shear stress, not the amount over time that actually matters for those endothelial adaptations.

So it's really important to do HIIT in that respect for sure.

Yeah.

So I think similar to kind of the cardiovascular stress, the endothelial stress, higher intensities of exercise are going to increase, you know, metabolic demand, increase your oxygen demand in your muscles, which is going to force your body to need, it needs to deliver more oxygen to your working muscles.

That means your heart is going to work harder.

Your stroke volume is going to go up.

So stroke volume for people who may not be familiar, it's the amount of blood that your heart is pumping out per beat.

So it fills with blood and it pumps it out and

usually expressed in something like liters per minute.

That would be your stroke volume.

It forces your stroke volume to go up.

Your heart rate obviously goes up during more vigorous exercise, but also your lungs are gonna fill and be stressed more to deliver more of that oxygen to your body.

And so that's another one of these reasons why vigorous and even zone two intensity of exercise up to a point, they're gonna stress the cardiac system, the heart and the lungs more.

That's gonna force your body to adapt and your heart is gonna get stronger.

Your lungs are gonna get stronger.

And I think one of the key adaptations there is obviously, again, the increase in stroke volume that you get.

That's one of the best predictors, or that's the main thing that increases when VO2 max increases.

So if you look at these studies showing, you know, what's the main adaptation that gives you a better VO2 max, it's higher stroke volume because that gives you a greater cardiac output.