VO2 Max during Exercise

What Is VO2 Max, and How Can You Increase it?

People tend to think of muscles as operating in a vacuum. Want good muscles, lift heavy things, right? It’s true that lifting is an important part of bulking muscle, but just like you have to eat right, you have to breathe right. That’s right, we’re talking about VO2 Max.

If you’re not familiar with this technical term, don’t worry. We’ll break down what it is, why it’s important, and how to improve yours.

Oxygen Composition Diagram VO2 Max

What Is VO2 Max?

We’ve given the rundown on how blood moves oxygen through the body in other articles, specifically in talking about iron as one of the key vitamins and minerals that contribute to muscle growth. VO2 Max takes the discussion a little further back to how oxygen gets into your blood in the first place: breathing.

Hear us out. This sounds pretty basic, but most people don’t care about which muscles are which or how muscles work. If you came across this page, you’ve decided to make that understanding a study and a better understanding of breathing factors into that study.

“VO2” is an abbreviation for “volume of oxygen” – in this case, the volume of gas that your lungs take in when you inhale (Abernathy et al., 164-165). VO2 Max can describe the most oxygen that you can get from a breath or it can describe the amount of oxygen required for a given activity, but in this article we stick to discussing it as the oxygen that your body has available.

This article won’t dive into why your body needs oxygen for energy – that’s a little deep for us (right now). Suffice it to say that at the heart of your body is a miraculous engine powered by the energy released by the splitting of molecules that have existed since the dawn of time. Think about that the next time you eat fast food.

For the average person, the average breath is about half-a-liter (Derickson, Tortora, 862), but your largest breath can be significantly larger than that. Numbers vary from person-to-person based on some things that you can change and some things that you can’t. More on that later.

A doctor or physical therapist can calculate your actual VO2 and VO2 Max, but most people don’t need to know their real numbers to be happy. It’s understanding the concept that’s important.

Why VO2 Max Is Important

Just like you have a resting heart rate that goes up when you exercise, your lungs have a resting intake volume that can go up as your body requires more oxygen for more energy for more activity. Just like your heart rate can only go so high, how much oxygen you can take in in a single breath eventually reaches a maximum. That maximum volume is your VO2 Max.

You may have picked up that rate and volume aren’t actually perfectly equatious. And that’s true – your breathing rate can and does also change to increase your available oxygen during exercise. However, your breathing rate isn’t as variable as your VO2 Max. That is to say, most people can’t increase their max breathing rate like you can increase your max lung capacity.

You can also improve your workout and your overall fitness by working on your heart rate and how much blood your heart moves per beat, a metric called “stroke volume,” but that’s a topic for another article.

How to Maximize Your VO2

As we’ve said above, your VO2 Max is pretty variable. Factors that you can’t change include the actual size of your lungs. You may also have respiratory conditions like asthma that can hold back your VO2 Max but, hopefully, working with a healthcare provider can help you get the most out of what you’ve got.

Some variables that you can directly or indirectly influence are:

  • Your lungs’ elasticity
  • Your lungs’ general health
  • Your core strength.

Maximizing Lung Elasticity

Your lungs are essentially just bags. Their internal volume decreases when you exhale, forcing air out, and their internal volume increases when you inhale, bringing air in. 

How big your lungs can get and how rapidly they can expand and contract depend on their elasticity. Your lungs naturally have elasticity, but, like stretching out a balloon before you blow it up, you can increase their elasticity by using them. 

As a result, aerobic exercises like running can make it so that your lungs can take in more oxygen no matter what activity you do next (Abernathy et al. 196-197). So, while running isn’t a favorite activity of bodybuilders, it can increase your body building performance by improving how much oxygen your lungs can make available to your muscles.

There are also things that you can do to decrease your lungs’ elasticity – mainly things like smoking and vaping. 

Tobacco smoke contains harmful chemicals that can stick to the insides of your lungs, preventing them from changing shape like they’re supposed to. Nicotine vapor, on the other hand, contains fluids that remain in your lungs after you exhale, essentially making less room in your lungs for actual oxygen – essentially a form of pneumonia.

If you vape or smoke, cut back with the aim of quitting if you can. If you can’t, talk to your healthcare provider about resources to help you.

Mind Your General Pulmonary Health

Pneumonia can also be caused by things like bacterial infections and it’s not the only respiratory condition that can hold back your performance by nerfing your VO2 Max. We’ve already touched on conditions like asthma. Unfortunately, conditions like asthma are on the rise largely due to things like pollution, which can be a big problem particularly in large cities.

Even if pollution doesn’t contribute to your asthma, it does decrease the percentage of oxygen in the air that you’re breathing – after all, the atmosphere isn’t all (or even mostly) oxygen. That isn’t to mention all of the other nasty things that you’re breathing in instead.

All of these conditions illustrate how your overall health and environment can impact your breathing. Again, it seems obvious, but a lot of people take it for granted. Further, don’t fall into the trap of thinking that because you work out your health will completely take care of itself. Be sure to have a healthy relationship with your doctor, even if you also see a personal trainer.

Develop Your “Muscles of Respiration”

Your muscles are elastic, but they aren’t muscular. That is to say, your lungs don’t expand and contract on their own in the same way that your heart does. Instead, muscles in your chest and core do the expanding and contracting and sort of bring your lungs along for the ride.

These muscles, called the “intercostal muscles” don’t get a lot of love and awareness in the muscle building community for two key reasons. The first is that they’re deep to other layers of muscle so you can’t really see them. The second is that they’re virtually impossible to target and actually work out. They’re small muscles that run in between your ribs.

The only real way to work them is through activities that involve rigorous breathing. Running is always a good choice, but swimming is preferable if you have access to water. A lot of the great things about swimming come from the physical properties of water, in this case, the pressure that the water exerts on your body from without that your intercostal muscles must work against. 

Your lungs actually fill with air when the pressure in your chest cavity decreases below the environmental pressure due to expansion (Derickson & Tortora, 863). Increasing the external pressure that your intercostal muscles have to overcome to expand your chest cavity (by working out in water instead of air) works those muscles harder.

More importantly, it’s okay for you to not be able to target a muscle in isolation because muscles don’t work in isolation. So, while doing core exercises won’t directly do a great deal for your intercostals, exercises – specifically toning exercises – for your abdominal region and lower back can help to develop the whole network that the intercostals operate in.

Develop Your Other Muscles too

Incidentally, using your muscles a lot also improves the efficiency with which your muscles access the oxygen that they have access to (Abernathy et al., 198). So, anaerobic exercises (high weight, low rep) doesn’t drastically increase your VO2 Max, but it can still help to streamline your oxygen metabolism.

VO2 Max As Your Age

There’s also one great reason to focus on improving your VO2 Max that we haven’t touched on yet, honestly, because it can be a little scary. We’ve already described your VO2 Max as something that isn’t just capable of being improved – it can also deteriorate. 

Your VO2 Max doesn’t just deteriorate if you do things like smoking. It also starts to decrease naturally as you age (ibid 187). This starts at a rate of around .5 percent to 1 percent/year , starting as early as age 20, increasing to as much as 10 percent by around age 45.

If you’re following along, you may be wondering if there is a point at which declining VO2 Max falls below the resting O2 requirements discussed earlier – meaning that your lungs no longer work well enough to keep you alive. Technically, that is possible, provided – and forgive our basal wording – nothing else gets you first.

For most people, this doesn’t occur. What does occur is declining VO2 Max such that exertion like running, lifting, or even regular moving around can become taxing. This is particularly true for people who lead a more sedentary lifestyle – even early in their lives.

Keep in mind too that how your body uses oxygen isn’t just dependent on the lungs. Cardiovascular health plays a huge factor as well. Taking care of your heart through vigorous activity, avoiding nicotine, keeping your weight in check, and keeping an eye on fats in your diet will play into these calculations too.

So far in this article, we’ve been looking at increasing your VO2 Max as something that you (probably) can (probably) should do right now to increase your short-term lifting performance. However, for those of you with an eye on your health and wellness decades down the road, thinking about VO2 Max sooner than later can lead to a longer and healthier life.

If you’re already over 20 (or 30, or 40…) keep an eye out, as an article on exercising as you age is on the docket at HTBM.

Max to the Moon?

It’s worth asking: if you can increase VO2 Max, even such that it holds out as you age, can it be increased indefinitely? The answer, unfortunately, is no. We’ve been focusing on VO2 Max as it relates specifically to your lungs in which case the absolute upper limit would simply be that your lungs can only expand to the extent of the available space in your chest.

Do keep in mind, however, that, as we’ve pointed out, how your body uses that oxygen is also reliant on factors other than strict pulmonary health. 

Your lungs can only take in so much oxygen, but you can also improve your heart rate and stroke volume to move that oxygenated blood more efficiently. Your heart can only move so much blood so fast, but keeping your arteries clear with a healthy diet can help that blood move.

You only have so much space in the healthiest arteries and veins, but getting the right amount of iron in your diet can help make sure that your blood cells are able to carry that oxygen. You can also work out to increase the efficiency with which your muscles use that oxygen once it gets to them.

The takeaway here is that if you ever look at one element of your health in isolation, there’s only so much that you can do. But, if you take a holistic approach to fitness and wellness, there’s always one more thing that you can do.

Go Run! Swim! Bike!

So, there you have it. VO2 Max is the maximum amount of oxygen that your body has available during physical activity. From a strictly pulmonary perspective, you can increase it by maintaining your general respiratory health, using your lungs, and developing your muscles – specifically your core muscles. 

Further Reading

Abernathy, Bruce; Hanrahan, Stephanie J.; McManus, Alison M.; Kippers, Vaughan; Pandy, Marcus G.; Mackinnon, Laurel. “Biophysical Foundations of Human Movement.” 3rd Ed. Human Kinetics. Champaign IL, USA. 2013..  
Derickson, Bryan & Tortora, Gerard J. “Principles of Anatomy & Physiology.” 14th Ed. Wiley. Hoboken NJ, USA. 2014.