Dr. Peter Attia

Anything that interrupts the production of ATP is fatal. So an extreme example of that is cyanide. Everyone's heard of cyanide as a poison. If you take cyanide, you'll be dead within seconds because cyanide blocks one of the transporters in the production of ATP. So it just gives you a sense of how critical it is to have an infinite and abundant supply of ATP. Oxygen is also essential for that.

Anything that interrupts the production of ATP is fatal. So an extreme example of that is cyanide. Everyone's heard of cyanide as a poison. If you take cyanide, you'll be dead within seconds because cyanide blocks one of the transporters in the production of ATP. So it just gives you a sense of how critical it is to have an infinite and abundant supply of ATP. Oxygen is also essential for that.

That's why without oxygen, you can only survive for a couple of minutes. longer than you can without cyanide, but not much longer. So how does it work? So we breathe in air and that air goes into our lungs and that air goes through our lungs into these distal things called capillaries where hemoglobin is bringing the waste product called carbon dioxide back to the lungs and there's a gradient of

That's why without oxygen, you can only survive for a couple of minutes. longer than you can without cyanide, but not much longer. So how does it work? So we breathe in air and that air goes into our lungs and that air goes through our lungs into these distal things called capillaries where hemoglobin is bringing the waste product called carbon dioxide back to the lungs and there's a gradient of

Partial pressure between oxygen and carbon dioxide such that a switch takes place. The air that we breathe in delivers some of its oxygen to the hemoglobin molecules. And the carbon dioxide diffuses off that into the air. And we breathe out air that is lower in oxygen and higher in carbon dioxide than what we breathed in. So if I go, that was high oxygen, low carbon dioxide. Whew.

Partial pressure between oxygen and carbon dioxide such that a switch takes place. The air that we breathe in delivers some of its oxygen to the hemoglobin molecules. And the carbon dioxide diffuses off that into the air. And we breathe out air that is lower in oxygen and higher in carbon dioxide than what we breathed in. So if I go, that was high oxygen, low carbon dioxide. Whew.

That was low oxygen, high carbon dioxide. And that's happening every second of every day. That oxygen, that hemoglobin molecule that's carrying oxygen is carrying it to every cell in my body because every cell in my body needs oxygen. And that cell in the body is taking the oxygen to run that chemical reaction to make ATP, and it's shuttling back carbon dioxide.

That was low oxygen, high carbon dioxide. And that's happening every second of every day. That oxygen, that hemoglobin molecule that's carrying oxygen is carrying it to every cell in my body because every cell in my body needs oxygen. And that cell in the body is taking the oxygen to run that chemical reaction to make ATP, and it's shuttling back carbon dioxide.

And it's just the most incredible thing in the world to imagine how frequently this is happening. And the more you exercise, the more you consume oxygen. So oxygen consumption is a proxy for energy demand. So... We can measure this. Now to do so, you have to put a mask on because I have to be able to measure very precisely two things.

And it's just the most incredible thing in the world to imagine how frequently this is happening. And the more you exercise, the more you consume oxygen. So oxygen consumption is a proxy for energy demand. So... We can measure this. Now to do so, you have to put a mask on because I have to be able to measure very precisely two things.

I have to be able to measure exactly the flow rate of air going in and out of your mouth. And I have to be able to measure very precisely the concentration of oxygen coming out. If I know those two things, I can calculate how many liters per minute of oxygen you are consuming. So you and I sitting here right now are probably consuming less than half a liter a minute.

I have to be able to measure exactly the flow rate of air going in and out of your mouth. And I have to be able to measure very precisely the concentration of oxygen coming out. If I know those two things, I can calculate how many liters per minute of oxygen you are consuming. So you and I sitting here right now are probably consuming less than half a liter a minute.

So call it 500 cc a minute of oxygen right now, because you have to consume some to be alive. And look, I'm moving my arms around and you're nodding and taking notes. So if you're sleeping, you might be consuming 300 milliliters of oxygen per minute. That's the lowest level. If you were to get up and we were to walk around here, that number might go up to 800 milliliters per minute.

So call it 500 cc a minute of oxygen right now, because you have to consume some to be alive. And look, I'm moving my arms around and you're nodding and taking notes. So if you're sleeping, you might be consuming 300 milliliters of oxygen per minute. That's the lowest level. If you were to get up and we were to walk around here, that number might go up to 800 milliliters per minute.

If we were to walk a little more briskly, we might be at a liter per minute of oxygen. If I said, let's go out in the parking lot and jog, well, we might get up to like 1.5 liters per minute. We pick up the pace a little bit, we'll get to two liters per minute. If I start really, really running us hard, we're gonna get to three and a half, four liters per minute.

If we were to walk a little more briskly, we might be at a liter per minute of oxygen. If I said, let's go out in the parking lot and jog, well, we might get up to like 1.5 liters per minute. We pick up the pace a little bit, we'll get to two liters per minute. If I start really, really running us hard, we're gonna get to three and a half, four liters per minute.

Well, at some point, I am going to push you so hard that you will achieve your maximum level of oxygen consumption. And if I push you any harder and faster, you won't extract more oxygen from the air. You may go faster, but you will do so through a process that does not involve the consumption of oxygen.

Well, at some point, I am going to push you so hard that you will achieve your maximum level of oxygen consumption. And if I push you any harder and faster, you won't extract more oxygen from the air. You may go faster, but you will do so through a process that does not involve the consumption of oxygen.

You will do so through an anaerobic glycolytic pathway, but you will have achieved your maximum consumption of oxygen. And that number has a very special name. It's called VO2 max. So VO2 max measured in liters per minute is the maximum amount of oxygen you can consume.

You will do so through an anaerobic glycolytic pathway, but you will have achieved your maximum consumption of oxygen. And that number has a very special name. It's called VO2 max. So VO2 max measured in liters per minute is the maximum amount of oxygen you can consume.