V02 Max and Longevity

Why Your Fitness Might Be One of the Most Important Numbers You Can Measure

If you could measure just one aspect of your physical fitness to get a better idea of how well your body is likely to cope with the decades ahead, what would you choose?

Your weight?

Your waist circumference?

Your resting heart rate?

How many press-ups you can do?

All of these tell us something. But there is another number that arguably tells us much more about the health and resilience of the human body: VO2 max.

And if you're interested in longevity, it is a number worth knowing.

At Sussex Longevity Clinic, we include accurate, clinical-grade VO2 max testing as part of our longevity screening in Brighton and Hove. It gives us something that is surprisingly difficult to get from a standard health check: an objective measure of how well your body can take in, transport and use oxygen when you exercise.

It is, in other words, a pretty good test of the engine.

So, what exactly is VO2 max?

VO2 max stands for volume of oxygen maximum.

Put simply, it is the maximum amount of oxygen your body can use during intense exercise, expressed as millilitres of oxygen per kilogram of body weight per minute (ml/kg/min).

When you exercise, your muscles need oxygen to help produce energy.

Your lungs have to get oxygen into your bloodstream. Your heart has to pump that oxygen-rich blood around your body. Your blood vessels have to deliver it where it is needed. Your muscles then have to extract the oxygen and use it to produce energy.

VO2 max therefore isn't really a measurement of one individual organ.

It is a measurement of the whole system working together.

That makes it particularly interesting from a longevity perspective.

Why does VO2 max matter for longevity?

This is where things get interesting.

For decades, researchers have followed large groups of people and looked at how cardiorespiratory fitness relates to their health outcomes.

The pattern is remarkably consistent: people with higher levels of cardiorespiratory fitness tend to live longer and have lower rates of cardiovascular disease and other major health problems.

This is why the American Heart Association has argued that cardiorespiratory fitness should be treated rather like a clinical vital sign.

That is quite a statement.

And it makes sense when you think about what VO2 max actually represents.

A high VO2 max generally means your cardiovascular and respiratory systems, blood vessels and muscles are capable of working together efficiently under stress.

And that capacity matters.

VO2 max isn't just about being a good runner

This is an important point.

You don't have to be a runner or cyclist to care about VO2 max.

You don't even have to particularly enjoy exercise.

Your VO2 max is a measure of your cardiorespiratory fitness, not your sporting ability.

A cyclist can have an excellent VO2 max. So can a rower, swimmer, hill walker or someone who trains on a bike in their garage.

Equally, someone who can run a surprisingly fast 5K doesn't necessarily have the VO2 max you'd expect.

And this brings us to an important misconception.

VO2 max isn't a test of how much you can suffer

We've all seen the sort of fitness test where someone finishes completely destroyed, collapses onto the floor and proudly announces that they've "given it everything". That's not necessarily a VO2 max test.

VO2 max isn't simply a measure of how much pain you can tolerate. It isn't a test of how motivated you are. It isn't a measure of how efficiently you run. And it isn't simply a measure of how fast you can complete a particular distance.

Your running technique, cycling experience, muscular strength, familiarity with exercise testing and willingness to push yourself can all influence performance.

But a properly conducted VO2 max test is measuring something much more specific: how much oxygen your body is actually consuming as exercise intensity increases towards your maximum capacity.

That's why accurate testing matters.

Why your smartwatch isn't quite the same thing

Modern watches and fitness trackers can be incredibly useful.

They can give you a rough estimate of VO2 max based on information such as your heart rate, speed, pace, age and activity data. But it isn't the same thing as directly measuring oxygen consumption.

There is an important distinction between estimating VO2 max and measuring it.

If you're interested in your VO2 max because you want to understand your health and longevity, rather than simply watching a number go up and down on your wrist, getting an accurate baseline can therefore be extremely valuable.

What does a VO2 max test actually tell you?

A VO2 max result gives you a number. But the number is only the beginning.

Your result can be considered alongside your age, sex, body composition, blood pressure, metabolic health, strength, physical activity, lifestyle and other markers of health. That gives us a much more useful picture.

For example, you might discover that your VO2 max is excellent. Great. It means that something you're currently doing appears to be working. You can continue building on it.

Alternatively, you might discover that your VO2 max isn't where you thought it was. That can be an uncomfortable result. But it's also potentially one of the most useful things you could find out.

Because unlike your date of birth, your VO2 max is not fixed.

Fitness is trainable.

The good news: you don't need to become an endurance athlete

Improving VO2 max doesn't necessarily mean running marathons or spending six hours a week on a bike.

Different types and intensities of exercise can contribute to improving cardiorespiratory fitness, and the right approach depends on where you're starting from. For one person, that might mean introducing more regular aerobic exercise. For another, it might mean adding some structured higher-intensity work. For someone else, the priority might simply be moving from a very low level of fitness to a moderate one.

And this is one of the reasons we like measuring things.

Instead of blindly following whatever the latest fitness influencer happens to be recommending, you can establish where you are now, make an informed plan, and test again later.

You can find out whether the plan is actually working.

Your VO2 max is a piece of the longevity puzzle

There is no single number that tells you how long you're going to live. Anyone who tells you otherwise is selling something.

Longevity is complicated. Genetics matter. Blood pressure matters. Metabolic health matters. Smoking matters. Strength matters. Muscle mass matters. Sleep matters. Social connection matters. Your medical history matters.

But VO2 max is particularly interesting because it captures something that many other health measurements don't: your body's ability to perform under physical demand.

And that capacity becomes increasingly important as we get older.

Think about what happens when you are 80. Being able to climb stairs, carry shopping, walk uphill, get up from the floor, travel, play with your grandchildren or recover from an illness isn't really about looking fit.

It's about having reserve capacity.

If everyday life requires 20 units of physical capacity and you have 100, you've got plenty of room to cope when something goes wrong. If you have 25 and everyday life requires 20, a relatively small setback can suddenly become a major problem.

That physical reserve is one of the reasons cardiorespiratory fitness is so interesting in the context of healthy ageing.

VO2 Max Testing in Brighton and Hove

At Sussex Longevity Clinic, we include VO2 max testing as part of our comprehensive longevity screening.

We use clinical-grade VO2 max testing equipment to directly assess your cardiorespiratory fitness, rather than relying solely on a smartwatch or an estimated calculation.

The aim isn't to give you a number and send you home. It's to put that number into context.

You might find that your current training and lifestyle are working brilliantly. That's good news.

You might discover that your cardiovascular fitness is lower than you expected. That isn't necessarily bad news either.

It simply gives you information. And information gives you options.

We can help you understand what your result means, how it fits alongside the other aspects of your health, and what you can realistically do to improve it.

The most useful fitness number might be the one you don't know yet

There's a slightly strange thing about modern health.

We can tell you our step count to the nearest 100.

We know our resting heart rate.

We know how many calories our watch thinks we've burned.

We know our sleep score.

We might even know our blood glucose.

But many otherwise healthy people have absolutely no idea how fit their cardiovascular system actually is.

If you're interested in longevity in Brighton and Hove, VO2 max is a very good place to start.

Not because it predicts your exact lifespan.

It doesn't.

But because it provides a remarkably useful window into your cardiorespiratory fitness — and because the evidence linking higher fitness with better long-term health is now difficult to ignore.

Most importantly, it's something you can change.

You can't change your age.

You can't change your genetics.

But you can improve your fitness.

And knowing where you're starting from is a pretty good first step.

Ready to find out your VO2 max?

If you'd like to understand your current fitness and how it fits into the bigger picture of your long-term health, we'd love to help.

Email us at admin@sussexlongevity.com to book your full longevity screening at Sussex Longevity Clinic in Brighton and Hove.

Your screening will give you a detailed picture of your current health and fitness, including an accurate measurement of your VO2 max — so you can understand what's working, what might need attention, and what you can do next.

Know your numbers. Understand your health. Build your future.