Brady Holmer

Your heart can pump more blood to your body.

You can use more oxygen during exercise.

And so that's one of the reasons why HIIT is so effective because it increases your oxygen demand more.

It forces your heart to work harder and you're improving that stroke volume.

And then same thing with the lungs.

I think the lungs are a little bit, not less adaptable, but they do adapt less because in a lot of people, unless you have asthma or something like that, the lungs are,

a little overbuilt maybe for exercise.

Like most of us have plenty of lung function, but the heart is really what's going to adapt there.

And so I think that, you know, again, is why we see this efficiency with his vigorous intensity exercise in this study and in others, because again,

you're just, the heart is being stressed more and you're gonna have a stronger heart if you're engaging in more higher intensity activities that are forcing the heart to adapt.

Going back to Ben Levine, I think he cited that similar study, but he talked about how, especially after say age 50, 60, 70, you need,

these higher intensities, again, it doesn't have to be hit, but it has to be pretty vigorous to force the heart to adapt and prevent cardiac fibrosis, cardiac stiffening of the heart.

If you don't get that high intensity training, you know, like low intensity really just doesn't cut it.

And so, you know, in this study, the cohort that we're talking about

They were aged 40 to 79.

So that might be why vigorous exercise had this outsized benefit on specifically cardiovascular outcomes, that eight to one ratio, like you mentioned, that incredible, like higher than some of these other outcomes.

So I think that's why there was that outsized benefit as well.

For sure.

And after about age 30 to 40 into your 50s, your VO2 max starts to decline about 10% per decade.

So if you're not doing something to maintain that, yes, you can build it up as much as you can into your 30s and 40s.