Increasing VO₂ max

I’m not a professional runner. I never was. Actually 6 years ago I hated running and I didn’t understand what’s the point of it; going somewhere without finish line. But 5 years ago it changed, I gave it a chance and found a goal that I achieved a year later: running a half marathon.
Nowadays, especially during the COVID-19 quarantine, it’s one of the best ways to keep my health. But distance running takes a lot of time that I don’t want to invest into this sport; so instead of going for more and more kilometers now my goal is to increase VO₂ max.

Increase what?

The VO₂ max “is the maximum rate of oxygen consumption measured during incremental exercise; that is, exercise of increasing intensity. The name is derived from three abbreviations: “V” for volume, “O₂” for oxygen, and “max” for maximum.” - Wikipedia
Increasing it means your physical performance and endurance gets better; your muscles burn oxygen to generate power, and, naturally, the more oxygen your muscles can burn the more power they can generate for you, thus, you’ll have more power. The two main factors that have effect on the value are the oxygen transport system (lungs and the heart that circulates the blood) and the muscles (that will utilise the oxygen-filled blood, they must have high capillary density). So, working on improving this performance indicator means your lungs, heart and muscles will also improve along the way.

How to do it?

There are two easy ways: interval- and hill runs. You can find plenty of training plans and tips, I won’t write yet another one; plus running isn’t my profession, others know things in this topic much better, believe me.
In my case, hill run training is the most obvious, where I live I can find an upward within 200 meters in any direction and even though I include it in every session, based on my experience, after a time the endurance increases slowly. I didn’t run for a bit more than half a year in 2019 and my VO₂ max fell from 50 (in July) to 46 (in November). True, I measure it with my watch, not in a laboratory, still, I like to know how my performance evolves and it’s a way to see it. So, since November I try to go on as much hills as I can (I have 90 meters elevation per exercise, in average), and my indicator went back to 49 recently, in April.

How to determine it?

The only trustworthy way is in a laboratory. They have the equipment to record everything (amount of air you breath in and out, for example) it requires to calculate your accurate VO₂ max; every other device gives only approximate value. Nowadays most of the fitness- and smart watches capable to do it, you need to start a run or cycling activity and maintain a fast pace for an extended time. Different equipments do it differently, you need to do some research for yours to know the exact process or calculation.

Things worth reading

How to Boost Your Cardio Fitness - Runner’s World
VO2 max: Everything you need to know - cnet
How Important is VO2 Max? What Does Yours Actually Mean? - RunnersConnect

What Is VO2 Max And How Can You Increase It? - The Running Channel
What’s The Fastest Way To Increase VO2 Max - EndurElite
How To Improve Your VO2 Max - Global Cycling Network