What My VO₂ Taught Me — And Why I Never Measured It Before

It started with a morning routine.

I checked my resting heart rate. Looked at how I slept. Scrolled through my step count. Then paused and thought:

"Wait… how much oxygen am I actually using?"

I’ve tracked every number my watch throws at me — but not this.
So I started digging. That’s how I found the Fick Calculator at fick-calculator.com.

That one number? Changed the way I look at recovery, stress, and performance.

What Is VO₂ — And Why Didn’t Anyone Tell Me?

VO₂ is your oxygen consumption per minute. Not to be confused with VO₂ max (the max you hit during intense cardio), this is the actual amount of oxygen your body uses right now.

It’s how efficiently your body turns air into energy.

High VO₂? You’re efficient, recovered, and metabolically active.
Low VO₂? You might be stressed, under-recovered, or simply sitting too much.

The Fick Principle, Simplified

At first, it sounded like something from medical school:

VO₂ = CO × (CaO₂ – CvO₂)

But here’s the simple version:
Your heart pumps blood. That blood carries oxygen. Your tissues take what they need and send the rest back. The Fick formula calculates the difference.

It’s like checking how much fuel your engine actually burns per minute.

I Tried the Fick Calculator

I went to fick-calculator.com.
Entered three things:

• My estimated cardiac output (CO)

• Arterial oxygen content (CaO₂)

• Venous oxygen content (CvO₂)

Click. Done.

I saw my VO₂. It wasn’t terrible, but lower than I expected. I had been feeling tired, and now I had data to support it. That gave me something to work on — and track again later.

What That One Number Can Reveal

• If your VO₂ is low, it might mean poor recovery, poor sleep, dehydration, or high stress.

• If it’s high, your system is working efficiently — good oxygen delivery, good extraction, strong metabolic function.

In short: it’s a metabolic mirror.

And you don’t need to be a pro athlete to use it.

Why Everyone Should Check It

Oxygen is energy.
Every cell in your body relies on it.

If you care about:

• Longevity

• Recovery

• Training

• Stress management

• Cognitive sharpness

Then VO₂ isn’t a “nice-to-have”. It’s essential.

My Takeaway: Nobody Taught Me to Track What Matters

We count steps, calories, heartbeats — but never oxygen use.

The Fick Calculator changed that for me.
And it can for you, too.

Go check your VO₂ now: fick-calculator.com
It only takes two minutes — and you’ll never look at breathing the same again.