What is VO2max (why it's important for longevity) | ft. Dr. Brandon Sawyer

[Music] so the vo2 max is not actually a measure of how fast you are at a given distance

or a given pace really it's a measure of how much oxygen your body can utilize given your heart's ability to pump blood your blood's ability to carry that oxygen and your muscles ability to

utilize that oxygen you get a resultant vo2 max number which is usually scaled by kilograms of body weight or you can give it in absolute terms for cyclists absolute may be more

important for sports like running the scaled version is more important the cool thing though is that there are a lot of tools that exist such as coach jack daniel's vdot calculators and his tables that

correlate a what they call a v dot score which is a derivative of the vo2 max with various training paces and estimated personal bests across a variety of

distances so for instance let's say that i had a vo2 max of 50 well i could look that up on the vo2 max tables and it would give me an expected time that i would be able to run if i

was training for specific events let's say the mile or the 10k or the marathon let's talk to dr brandon sawyer who's actually one of my colleagues here at plnu and has done a lot of research

regarding vo2 max testing so we're just going to pop over to his office he has to put up with all of my lecture recording because we share a wall uh dr sawyer can you tell us a little

bit about your background with vo2 max testing yeah for sure so starting with my uh my master's degree at i i did at university of virginia in charlottesville

i worked with a couple of experts in vo2 max testing um dr glenn gazer and dr art weltman and and yeah did some studies with them early on and

trying to understand the physiology of it as well as the physiology of critical power or critical velocity which would be kind of maximal sustainable intensity so kind of in those areas and then since then

since i've been in point loma i've done quite a bit of work on trying to just refine testing methodology for vo2 max to be able to really identify when somebody reaches a true max and when

they don't can you tell us a little bit about the verification phase yeah absolutely so so really the original definition of the vo2 max was when

somebody increases intensity of of the work of the exercise they're doing but their oxygen consumption does not increase so for example somebody's running on a

treadmill six miles per hour we a lot of common protocol we use would be go up one percent per minute um let's say they get to ten ten percent grade they're going six miles per hour their vo2 is at

let's say 50. um we we take them up to 11 and their vo2 stays at 50. we know that their body actually requires more oxygen to be consumed to to exercise at that

higher intensity but if it doesn't actually increase then we call that the vo2 plateau and so that that's kind of the initial criteria that that was observed in research was an increase in

intensity with no increase in oxygen uptake and so that's kind of what's known as a primary criteria for vo2 max so meaning that if we see that then yeah we know that's the true vo2 max

but problem is we don't we don't always see that we don't see it very often so what people did was come up with secondary criteria which pretty much means we look at their blood lactate levels at max we look at their

respiratory exchange ratio which is their co2 divided by their o2 or we can look at their perceived exertion we can look at their maximal heart rate so kind of trying to find some numbers

that might be threshold values for all right if they if they achieved a certain number with all of those then that means they reached a true max problem is those are also very problematic they don't sometimes people

achieve those much before they reach max sometimes people reach a plateau in vo2 but they don't achieve any of those things so it's kind of all over the place there so kind of our third option which is what

we're what we're really moving towards now is the verification phase which is kind of a way to artificially create a vo2 plateau so pretty much we if we go back to that same example we've got got

that person to six miles per hour and 11 on the treadmill let's say their vo2 was 50. what we would do would be let them kind of cool down do an active cooldown

for 10 to 15 minutes and then we put them back on the treadmill at about 10 percent greater of a work rate so that may be maybe 6.3 miles per hour and maybe 12

percent great get them up about 10 percent higher and then if their vo2 still doesn't go over that 50 it's still plateaus then we know for sure that yeah that is the maximum amount of oxygen that they can

take in and that's another key part to vo2 max system 2 is choosing the correct increment because part of part of a what's what's shown to be a good vo2max

test is that fatigue happens at a time in between 8 and 12 minutes and that's a really key part to designing a protocol to a vo2 max test if you have somebody that goes 25

minutes they might just stop because of more general fatigue not because of true oxygen limitation right if you design a protocol that only lasts four or five

minutes then their their oxygen uptake just might not have enough time to get all the way up to max and so the ideal range is right right in that 8 to 12 minute range and so what we what we do

typically is we actually will actually predict their vo2 max with some algorithms that have shown to be pretty good they're just based on their height and their age and their weight and their sex and their physical

activity level and then we'll design a protocol that gets them to that predicted max right at 10 minutes so really vo2 max is known as

the gold standard measurement for cardio respiratory fitness is what it's called right so like the fitness level of your cardiovascular system your respiratory system

and it's a it's a great marker for cardiovascular health as well and so so if you if you took a bunch of measurements like percent body fat body weight

even cholesterol even blood cholesterol blood pressure things like that and then you also did a vo2 max on somebody and you use those to predict cardiovascular health over the next 10

to 20 years the best predictor of their health would be vo2 max by far much better than any of those so it's a very good marker of cardiometabolic health and then again back to the fitness

it is just kind of the gold standard measurement of fitness and so so getting that what's also known as aerobic capacity vo2 max it's just a really good test of your

cardiovascular system respiratory system your skeletal muscles your metabolic health of your skeletal muscle and so that's kind of one of the things that i love about vo2 max and why i love studying it is because

in order to really think about vo2max you have to think about everything involved in getting oxygen out of the air into your lungs put it onto your red blood cell pump it out of your heart

send it to your send it through your arteries down your capillaries extract it out and then actually use it in your muscle cells so anything along the way it could be a potential limiter

of vo2max and so in a lot of ways it really looks at a whole body function and so yeah it's a great marker of metabolic health cardio health

respiratory health all of those things awesome all right thanks dr sawyer yeah nice work nice work here we go [Music]