VO₂ Max - The Key to Smarter Training and Better Performance

Why Do Some Athletes Seem to Have Endless Stamina?
Have you ever watched someone run effortlessly for miles while you feel out of breath after just a few minutes? The difference often comes down to how well their body uses oxygen—which is exactly what VO₂ max measures.

VO₂ max tells us how much oxygen your body can take in and use during exercise. The higher your VO₂ max, the longer and harder you can work out before getting tired.

If you want to run longer, recover faster, and perform better, understanding VO₂ max is a game-changer. Let’s break it down in a way that actually makes sense.

What is VO₂ Max?
VO₂ max is a fancy term for how well your body uses oxygen when you’re working hard. It’s basically a score for your endurance and fitness level.
Think of It Like a Car Engine

• A big engine (high VO₂ max) = More power and better efficiency. You can go faster and farther without running out of gas.
• A small engine (low VO₂ max) = Less power and more stops for fuel. You get tired more quickly and need more breaks.

Another way to think of it: Your muscles need oxygen to keep moving. The better your body is at using oxygen, the longer you can exercise before feeling exhausted.

Why Does VO₂ Max Matter?
VO₂ max isn’t just a random number—it affects how long you can exercise, how quickly you recover, and even your long-term health.

• Better endurance – You can keep going without getting tired as fast.
• Faster recovery – Your body uses oxygen more efficiently, so you don’t feel drained after workouts.
• More energy – Your heart and lungs don’t have to work as hard, so exercise feels easier.
• Better overall health – Studies show higher VO₂ max levels are linked to a longer lifespan and a lower risk of heart disease. (Source: JAMA Cardiology, 2018)

How I Learned This the Hard Way
For years, I trained an athlete for Spartan Races—lots of running, climbing, and carrying heavy objects. We focused on building endurance, and when we tested VO₂ max during this time, the athlete had a solid balance between short bursts of speed (high-intensity training) and long-lasting stamina (aerobic endurance).
Then, we switched to CrossFit. For the next couple of years, we trained with high-intensity workouts, short bursts of effort, and lots of metcons. We thought that would make us even fitter.
When we took another VO₂ max test after two years of  CrossFit, the results were shocking.

• Our Zone 2 (low-intensity endurance) had suffered.
• Our Zone 5 (high-intensity power) had improved, but the gap between the two had gotten much bigger.
• We had lost some of our long-lasting endurance.

We were still powerful, but our ability to keep going for long periods had taken a hit.
Why Did This Happen?
When you only do high-intensity workouts, your body adapts to short bursts of power but forgets how to efficiently use oxygen for endurance.

• Your body gets worse at burning fat for fuel, which means you burn out faster.
• Your heart and lungs don’t get as much low-intensity training, which makes long workouts feel harder.
• You rely more on quick energy (sugar) instead of steady energy (oxygen).

Basically, we had gotten really good at sprinting but worse at lasting the long haul.
How We Fixed It
Once we realized what happened, we added back low-intensity training (Zone 2).

• Long, slow workouts – Running, rowing, cycling at an easy pace for 45-60 minutes.
• Lower-intensity CrossFit sessions – Workouts that weren’t just “go hard or go home.”
• Pacing strategy – Mixing up efforts to train both short bursts and long endurance.

Within a few months, we felt a huge difference. The athlete wasn’t just strong and powerful—they could sustain that strength for longer without getting exhausted.

How is a VO₂ Max Test Done?
A VO₂ max test shows how well your body uses oxygen. Here’s how it works:

1. You wear a special mask that tracks your oxygen levels.
2. You run on a treadmill or bike while the intensity gradually increases.
3. The test ends when you hit your max effort.

This test pushes you to your limit but gives you real data about your fitness level.
How to Prepare for a VO₂ Max Test

• Avoid caffeine or a big meal before the test.
• If you have asthma or heart issues, check with your doctor.
• Expect to go all out—it’s called max effort for a reason!

Smarter Training = Better Results
VO₂ max isn’t just for elite athletes—it’s a simple way to measure and improve your endurance.

If you’re feeling stuck in your training, check your balance of intensity and endurance. Mixing high-intensity training with lower-intensity Zone 2 work can make you stronger, faster, and more efficient over time.

Train smarter, not just harder—and you’ll see the difference.

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