Why does cardiorespiratory fitness (VO2max) determine our longevity?

Some scientific insights explaining why a high VO2max might be a powerful marker for longevity.

What means VO2max?

Physiologically, VO2 max is telling you how quickly you can take oxygen from the air into your lungs, get it into your blood, pump it to your muscles, and then have your muscles use it in the metabolic processes that will provide energy to move you.

VO2max is typically expressed in terms of the volume of oxygen a person can use, per kilogram of body weight, per minute

My VO2max for example is: 47 ml/kg/min, which ranks me (according to Mandasager et al. JAMA 2018) in the men category 60-69 years at the lower end of "Elite" category (see graph below)

According to Dr. Mike Joyner, an exercise physiologist and researcher at the Mayo Clinic, an average 45 years old man will have a VO2max of around 40 ml/kg/min, while an elite endurance athlete will likely score in the high 60s and above. An unfit person in their 30s or 40s, on the other hand, might score only in the high 20s on a VO2max test.

Performance Group by VO"max (Source: Mandsager et al. JAMA New Open, Oct. 2018

Where would you rank in this graph?

The importance of VO2max for longevity

VO2max is a strong predictor of overall health and lifespan. In other words, higher VO2max levels are associated with a longer life and a lower risk of chronic diseases.

VO2max is not only crucial for endurance sports but also plays a significant role in daily life, manifesting as physical stamina. The higher your VO2max, the more energy you will have for any activity you enjoy, whether it's hiking or shopping.

Conversely, the association between a low VO2max and mortality is so clear that VO2max is considered one of the most powerful predictors of lifespan.

What does the Science say?

The 2018 study in JAMA that followed more than 120’000 people found that higher VO2max was associated with lower mortality across the board. The fittest people had the lowest mortality rates – by a staggering margin.

Some example explanations of the above graph:

A person who smokes has a 40% greater risk of all-cause mortality (risk of dying at any moment) than someone who does not smoke, representing a hazard ratio or HR of 1.40?

Some with a VO2max of Below Average compared to a person with VO2max ?of Above Average shows a HR of 1.41, in other words this person is 41% more likely to die in the coming year, the exact same HR of a smoker to a non-smoker. And a person with a Low VO2max compared to a person with a High VO2max shows a HR of 3.9 which means almost 300% difference in mortality risk.?

These figures were confirmed by a much larger and more recent study published in 2022 in the Journal of the American College of Cardiology, looking at data from 750’000 US veterans aged 30-95.

The above table expresses all-cause mortality risk for different fitness levels compared to individuals in the top 2% of VO2max for their age and sex (extreme fitness level) and for the various comorbidities. Fitness groups are divided by percentile: Least (<20th ?percentile); Low (21-40th ?percentile); Moderate (41-60th ?percentile): Fit (61-80th percentile); High (81-97th percentile).

Being unfit carried a greater risk than any of the cardiac risk factors examined”, the authors concluded.

All this data probably cannot tell us that simply having a high VO2max will offset high blood-pressure or smoking habits, as much as the hazard ratios suggest it might. Without a randomized controlled trial we can’t know for sure. But what we certainly can conclude is that having a higher VO2max is better for your health and longevity than having a lower VO2max. Period.

How can you measure your VO2max?

Measuring VO2max can be done through various methods, ranging from laboratory tests to field tests. Here are some common approaches:

Laboratory Testing (gold standard)

Maximal Exercise Test: It involves exercising on a treadmill or stationary bike at increasing intensities while wearing a mask that measures oxygen and carbon dioxide exchange. The test continues until the participant reaches exhaustion: have fun :))

Where can I conduct this test?

• Universities and research institutions
• Sports Medicine Clinics
• Private Fitness and Performance Centers

How much does it cost?

Depending which provider you pick, but it ranges between 200-400.-

Field Tests:

1. Cooper Test:

This involves running as far as possible in 12 minutes. The distance covered is used to estimate VO2max. The correlation coefficient is between 0.70-0.90, which can be considered as a reliable and valid method.

Estimation method: VO2 max = (D – 504)/ 45

2. Beep Test (20 meter Shuttle Run)

This test involves running back and forth between two lines 20 meters apart, with the speed increasing each minute. The level reached before exhaustion is used to estimate VO2max. There are multiple free of charge Beep Test Apps to download. The correlation coefficient is 0.92 which is considered as rather strongly reliable.

Wearable Technology

Fitness Trackers and Smartwatches: Some advanced fitness trackers and smartwatches can estimate VO2max based on heart rate data collected during exercise. Reliability depending strongly of the device quality.

Online Calculators

These calculators are convenient but should be used with caution, as they may lack accuracy quite a bit.

My practical tip:

Whatever method you choose, focus on consistency: For the most accurate results, it's important to perform the tests under consistent conditions!

How can you train VO2max?

Bear in mind that training and testing VO2max does hurt ? and I wouldn’t consider it as fun. To be honest as older I get as more I have to push myself to test and train it, but I know the investment is worth it.

?Basically it depends a bit what your actual fitness level is. For the sake of simplicity lets consider 2 scenarios:

Unfit individual (< average)

Try to incorporate 1 x VO2max training-session per week.

Examples:

• Walking on a treadmill (ca. 30 mins) 5 mins Zone 2 pace: meaning you still can talk > 4 x 3 mins walking uphill intervals: choose an incline level which you can sustain but on a level where you wouldn't be able to talk anymore. > pause for 3 mins in between the intervals (very slow flat walking)
• Spinning-Bike: you can apply the same protocol
• No Gym: Walking outdoors (like walking on a treadmill just try to find the appropriate terrain), or swimming.

Note: I would avoid to start doing the training by running as it might be too taxing on your system (compression!)

Fit individual (> average)

Try to incorporate 1 x VO2max training-session per week.

The most effective High Intensity (VO2max) protocols are:

• 4x4 Intervals with 4 mins relax in between (easy moving): The suggested perception of exertion during the interval:

-1st minute: you might think it is too easy

-2nd minute: you think it could be worse

-3rd minute: it really starts kicking in

-4th minute: you hardly make this minute and you feel totally "cooked" afterwards?

• 8x8 mins Intervals: You can apply those protocols to multiple sports like: swimming, biking, running, rowing. Again 8 mins pausing in between intervals (easy moving)

My personal protocol:

?I train VO2max once per week based on the following protocol: It is called “

"Acid Bath", performed by Lance Armstrong and friends.

It is a combination of 3 disciplines: SkiErg, rowing and biking:

4 x 4 Intervalls. An interval looks as follows:

• SkiErg: 500m full-out
• Rowing: 500m full-out
• Biking: 1000m full-out

With running from the SkiErg to the rowing machine it takes me about 6 minutes/Interval. In between the intervals I do pause by just walking around for 6 minutes.

?Take away?

It is a fact that one of the prime hallmarks of aging is that our physical capacity erodes. To paraphrase Hemingway, this process happens in two ways: gradually, and then suddenly.?

But the way the physical capacity erodes is entirely up to us and science evidence clearly shows the strong association between cardiorespiratory fitness (and muscle strength: see next blog) and longevity. Therefore, the slogan is:

The name of the game is to stay in the game!

?Keep it up!

Resources:?

Physical Fitness and All-Cause Mortality: A Prospective Study of Healthy Men and Women (JAMA Network)?

Cardiorespiratory Fitness and Mortality Risk Across the Spectra of Age, Race and Sex, (Journal of the American College of Cardiology?

Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing (JAMA Network Open)