VO2 max- Your Oxygen-Maximizing Power

Happily Health

The only event at the first Olympics ever was a 192-meter run called the stade. Named after the length of the ancient Greek stadium from one end to the other, it was also, famously, the distance the mythical Greek hero Hercules could sprint on a single breath. Given that the current (mortal) world record for the longest breath-hold is about 22 minutes, it may seem a rather unimpressive feat for a superhuman being. That is, until you realize all such records are attempted underwater, in complete stillness, with the goal of conserving energy for as long as possible. Going all out without air may thus be a suitable exploit only for superheroes.

From lungs to cells: A journey of thousands of miles

It is worthwhile to be aware just why a continuous supply of air, or oxygen, is so important. We are “aerobic” beings which means that we need air, specifically oxygen (written as O2 as it comes in twos as a molecule), to burn fuel for energy. We can make ATP, the molecular energy packets, without oxygen as well but this anaerobic process is really inefficient and our bodies won’t permit it for long. Try pinching your nose and keeping your mouth closed for longer than 30 seconds and you’ll hear every cell of your body revolt.

Our bodies have adapted to this with two special features of the cardiorespiratory system– a highly intricate blood vessel network (estimated to stretch for about 100,000 miles) that can deliver O2 to any of the trillions of cells that need it and a robust pumping mechanism that makes sure this distance can be covered quickly. 

When you inhale, the air floods millions of air sacs in your lungs called alveoli from where O2 is filtered into tiny capillaries of the pulmonary veins. Once in your bloodstream, the O2 rides on the hemoglobin in your RBCs, through an extensive maze of arteries and capillaries, till it reaches its final destination- the ATP-making factories in your cells called mitochondria. To speed this journey along, the pulmonary veins attach to the heart, which can quickly pump the newly oxygenated blood to each living cell of your body.

Modern-day superheroes are all about air

Compare the impressive musculature of a sprinter with the rippling, but slender physique of an endurance runner and you can see that the latter is a more compact, fuel-efficient machine designed to go the distance. But the obvious dissimilarity on the surface hides an even bigger secret at the depths of the cardiorespiratory system. 

An Olympic-level 100-metre sprinter can maintain an average speed of about 35 km/h for a little more than 10 seconds. But an Olympic-level marathoner can sustain more than half this speed, at an average of 20 km/h, for more than 420 times the distance. To meet the demands of such an intense effort, the marathoner must develop the ability to burn fuel both rapidly and efficiently with the help of O2. Unlike the sprinter, he/she can’t be relying on the oxygen-less but inefficient anaerobic ATP production. They must develop the Ferrari engine of oxygen transport systems. 

VO2 max, your oxygen-gobbling power

Considering that less than 1% of us will ever run a marathon or participate in any such endurance event, forget competing at the Olympics, why is it relevant to us? It turns out that our aerobic capacity- the maximum O2 we can take up, deliver, and utilize in a minute- is a vital indicator of our health. So much so, that in 2016 the American Heart Association recommended that doctors consider the aerobic capacity, given the moniker VO2 max, as a vital sign.

They think your VO2 max score better indicates your chances of dying from disease than if you check the boxes for the better-known troublemakers such as smoking, hypertension, high cholesterol, and type 2 diabetes. So, don’t be surprised if in the near future your doctor, after checking your weight, BP, and pulse, asks you- just how much oxygen can you eat today? If the answer is less than 20 ml/kg/min, you may be in trouble. If it is greater than 70 ml/kg/min, you have a shot at the Olympics. 

To accurately measure your VO2 max you have to exercise with a breathing apparatus attached to your face, at increasing levels of intensity, until you are going as hard as you can. A simpler alternative is to make an estimate using some standard tests such as the fastest time in which you can walk 1 mile or the farthest you can run in 12 minutes. 

Or you can take the lazy way out and use a non-exercise estimate: https://www.worldfitnesslevel.org/#/

How to improve your VO2 max

Even the fastest race cars cannot do what our bodies do every day. We have the ability to keep adapting to meet fresh demands- provided we are asked politely, of course! Too much exercise too soon can drive us to injuries or worse. But if we gently push ourselves to exercise more and hence to demand more O2, our hearts remodel themselves to become larger and stronger so as to pump more blood with every stroke. Our blood vessels grow even more branches to provide a better supply to our cells. Even our mitochondria learn to guzzle O2 faster. 

No matter what your current VO2 max score, you can improve it by adopting regular aerobic exercise and ramping up the intensity now and then. The more muscle groups (and hence more mitochondria) involved, the better. If you are already exercising regularly, incorporate high-intensity interval training (HIIT) workouts into your regimen. These are the kinds that push you to go as hard as you can for short intervals of time. But make sure to do these only after a proper warm-up. 

And if you are a dedicated exercise junkie, know that interval training alone is no substitute for a well-rounded mix of exercises done at varying intensities. 

The happy takeaway

Your body is a finely-tuned oxygen delivery machine. Irrespective of  your age, gender, or level of fitness, placing a greater demand on this machine increases its ability to utilize oxygen. To do this you have to begin an aerobic training regimen and practice interval training. 

While there are many types of HIIT workouts, one of the quickest and easiest ways to get started is to periodically pretend to be a superhero. It’s easy- Take the stairs after your evening stroll. Jog a few meters in between a brisk walk. Sprint up a hill on your morning run. Do whatever it takes to get you breathing harder than usual. Remember to pat yourself on the cape when you’re done! 

Disclaimer 

As always, please do consult your Doctor/Physician before beginning with any exercise regimen. They will be in the best position to guide you about what you can or cannot do, given your age, health status, physical fitness levels, and other conditions unique to you.

About Happily Health

Happily Health truly believes in gradual and sustainable changes that can help you build a healthier lifestyle one step at a time. But we know this isn’t easy. So we made it simple and fun!