 So we talk about aerobic capacity. Lot of stuff I know. I'm trying to keep it fun. That's why Michelin Boy was there. Cardiorespiratory training, improvements in cardiovascular fitness. Some people, string training is a little controversial in this way. Typically it's assessed by a treadmill test. And it's an important risk factor in all cause mortality. Now, should any of you be in a situation where you have to take a treadmill test for insurance? I have a suggestion. Practice a treadmill test the month prior to doing that. You will score so much better in spite of the fact that you have not gotten fitter because there is a skill component involved in constantly adapting to the increasing levels of the treadmill. When you do a treadmill test, every three minutes they're increasing the height of the treadmill, the grade and the speed, typically. If you practice that, you're much better as a result. So mortality and comorbidity, they're associated with coronary heart disease in men and women in this particular treadmill test in all cause mortality. And high levels of physical fitness delay this, mostly because of that lowered rate of cardiovascular disease. So you go on Google and you search heart attack. This guy showed up with some memes. Am I the only one who thinks that this isn't a heart attack, but possibly an o-face? What's going on down here? What's going on down here? And I do like his old receipt machine here as well. That's always a good time. So that's what we're talking about. If we talk about aerobic capacity to a certain extent, we're also talking about heart attack prevention VO2 max things of that nature. So in this particular study, treadmill walking endurance increases 38% and an 80% of VO2 max in these elderly individuals, even though VO2 max has not changed. VO2 max is a monopoly money measure of how much oxygen you can consume and use at the muscle tissue level. The thing is is that you can increase your endurance without increasing your VO2 max. It's mostly set by genetics. And so people for a while there once they figured out, ah, VO2 max, let's drive this thing in the moon. You don't get much more than 20% training for it specifically above your genetic level. And that doesn't mean that you're going to suddenly be some sort of world champion athlete. You have marathon champions between 60 VO2 and 90 VO2. So it's an interesting measure that doesn't mean anything. But if you're going to argue with someone and their only term is VO2 max, now you've gotten something to say like, hey, buddy, I can argue with you on that and show you that strength training on top of making you look better naked, made your ticker better as well, even in their arena of choice. So 12 weeks of high-intensity strength training increases VO2 max by an average of 1.9 milliliters per kilogram per minute. You see why it's a bit of monopoly money. You can move your weight up and down. In my case, this would be about a 5% increase. My VO2 max is 47 without doing any cardio. In order to be at the elite level according to the list that they put out there, you have to be at 50. So that's not bad training 13 minutes once a week. And they did it in 72-year-old men. And again, I talked about the compromise with aging in the heart earlier. Biopsy showed a 15% increase in capillary density and 38% increase in centrate synthase activity. Capillary density is typically only seen increases in this. It's the amount of arterials feeding the muscle tissue directly, supplying the blood into them. Normally what happens when you strength train is that your muscles get bigger and you see a reduction in that capillary density because the volume of those capillaries has stayed the same. You still get just as much blood into the muscle tissue. Of course, this doesn't matter, as I told you earlier, because you're more efficient. So you don't need more capillaries if you can move more blood through them. The other thing here is that centrate synthase, I want you all to go back to high school biology, chemistry, physiology, it shows up in all of these, is a rate limiting step, is the rate limiting step in the Krebs cycle, citric acid cycle. So acetyl-CoA is a substrate that glucose, glycogen, fat, and protein can all move into and become in the body that passes into the cell. And the first thing it has to be acted upon is citrate synthase before it becomes citrate and starts moving around and throwing off ATP like mad. If you can increase this rate limiting step by 38%, you can deal with more substrate coming down. You are a more aerobic animal without doing any aerobics because we're just a bag of chemical reactions. So if you can get these rate limiting steps bumped up, you can run with your friends, sprint past them, and keep going without ever doing any cardio. I think you would have something better to do than go jogging with your friends, of course. So in expansive review of depth and breadth of adaptations has been published by 20-ome Convention alumni James Steele, Deuce. There's actually a James Steele, the third. If you accidentally type in three I's. And Doug McGuff, magical deity. I mean, medical doctor. Saw that from actually Doug's got a great story. He's been writing articles and things for years and years and years. And he had this one talking about sort of bringing doctors back down to Earth. And he said two things. He said, MD does not mean magical deity. And you might think being a doctor is a great job and it's hugely rewarding in a number of ways. But how many of you have to stick your finger in a sphincter on a daily basis? That's why they pay him the big bucks.