Want to maintain your physical abilities throughout life? Then focus on improving your VO2 max!

Without risking serious injury, the average person can survive without…

• Food for 21-30 days

• Water for 3-4 days

• Sleep for 3 days

• Oxygen for 4 minutes

Which one of these stands out from the rest? (It’s the one measured in minutes.)

You would think that monitoring oxygen fitness would be a core part of healthcare would you not?

Doctors monitor all sorts of things about us as we age:

• Blood pressure

• Cancer screenings (breast/colonoscopy)

• Height/weight

• Blood panels to check lipid levels, fasting glucose (to screen for diabetes), etc

But has your doctor ever suggested that you have your VO2 Max measured? Unlikely.

Historically VO2 Max tests have been used almost exclusively by runners and other athletes seeking to optimize performance. We’re trying to change that.

VO2 Max is a measure of how much oxygen your body consumes at maximum exertion and intensity. Higher is better. We measure it by running really fast on a treadmill (or as fast as you can), or by peddling really hard on a bike for about 1 minute, while wearing a mask that measures oxygen intake. The machine connected to the mask calculates how much O2 you are using at this “maximum point of exertion”.

Oxygen is literally the most important thing to sustaining life.

Earth’s atmosphere is about 21% oxygen, 78% nitrogen, and 1% other gases (which includes the all-famous carbon dioxide).

4 billion years ago Earth didn’t really have an atmosphere and there was certainly no oxygen to be found. Where did the oxygen come from you ask? Great question. The answer is bacteria.

The first bacteria were heterotrophic, meaning they got their food from the environment just like animals and humans. These bacteria evolved into autotrophs, which as the name implies can make their own food. Plants and trees are autotrophs, feeding themselves through photosynthesis. It was these autotrophic bacteria that started filling the Earth’s atmosphere with oxygen (a biproduct of photosynthesis).

Oxygen kick-started life as we know it. In the human body, oxygen is responsible for fueling:

• The replacement of hundreds of billions of cells per day

• The cells that comprise our immune system

• Our eyes

• Our metabolism, meaning it is responsible for helping us turn nutrients into the energy that enables our muscles to move and our brains to think

There is more, but I think we’ve got enough to establish how crucial oxygen is. Let’s move on.

If your VO2 Max is increasing then at least three big health benefits are taking place:

1. Your body is increasing the efficiency with which it diffuses oxygen from your lungs into your blood

2. Your heart is getting stronger both by increasing its beats-per-minute capacity and increasing the volume of blood that can be pumped during each contraction

3. You are gaining more mitochondria and making the mitochondria you already have more efficient at producing energy

Sadly, as you might have guessed, as we age our VO2 Max declines by default - unless we actively fight back.

One of the things we do with our patients (and think most doctors should do) is use real world examples to explain why things are important.

Here’s an example.

Each year after we turn 50 we lose an average of 2% of our muscle mass (again, this is only true if we don’t fight back, but sadly most people don’t!). A 2% loss in muscle mass translates into a 2-4% reduction in the amount of weight we can lift. Here’s what this looks like on a chart:

Let me put this into words. If you have a hard time lifting 50 pounds at age 50, then by age 60 you will have an equally hard time lifting 40.9 pounds, and by age 70 you will have an equally hard time lifting 33.4 pounds, and so on…

Isn’t it a bit more motivating to know that you need to be able to lift 50 pounds at age 50 if you want to be able to pick up your grandchild when you hit 80?

When it comes to our oxygen capacity we have a similar chart:

The lines show where the 85th, 50th, and 15th percentiles respectively fall by age. But the most important thing to note about the colored lines is how they decline with age. The purpose of this chart isn’t to make us depressed. The real purpose is to illustrate what physical activities we’ll be capable of for each different VO2 Max level, and to inspire us to try and move vertically up the chart no matter where our starting point is.

There’s one more thing we need to point out. VO2 max is measuring our all-out effort. Being ON one of the above lines only means that you’ll be able to sustain that activity for a short period of time. What we really want to focus on is being able to do the things we want to do for the length of time that people normally do them. We don’t want to cut the grass for five minutes, we want to cut it until the job is done. We don’t want to play 4 holes of golf, we want to play a full round!

As a rule of thumb, we’re only able to sustain about 60% of our VO2 Max. For context, the American College of Sports Medicine recommends aerobic training to take place at 60% to 80% of VO2 Max. Let’s look at another chart to make this easier to digest:

The red dot represents a hypothetical person. This person would only be able to do activities around the top of the orange area for a few minutes, and would find it completely impossible to do anything above the orange area. But, only activities in the red area would be possible for any extended period of time. Note that by the age of 65 they would be needing to take breaks mowing their lawn, and playing Golf would become difficult shortly after 65.

So, what do we need to do to move up the chart?

First, go get a VO2 Max test so that you can establish a baseline. Every person’s body is unique, and it’s important for you to learn what activities/fitness level is associated with your current score. While there are always exceptions, for the most part if you are able to maintain your score then you will be able to maintain your activity level.

Second, we suggest making it an objective to actually improve VO2 Max, rather than being satisfied with stasis or letting it decline. It is absolutely possible and anyone can do it. Increasing your VO2 Max doesn’t mean you have to start doing high intensity interval training and wind-sprints every day rain or shine. For most people, improving VO2 Max can be as simple as putting a couple points of extra resistance on a stationary bike, adding 2-3 degrees of incline on a treadmill while maintaining your prior pace, or adding a small hill to your morning walk.

The sad truth is that the rapid decline that takes place throughout life (declining slopes on lines are from population surveys) is not inevitable. The good news is it can be held at bay with moderate amounts of effort combined with annual or bi-annual testing to make sure that you are pushing yourself enough to maintain or improve your VO2 Max.