Zone 2: why all the hype??

Zone 2 Training: My Experience, the Science, and Why It Matters

If you’ve ever tried truly staying in Zone 2, you know it’s shockingly hard—especially if you’ve never intentionally trained there. I can confirm this firsthand. My running background has always been: finish a full day of school or work, lace up, and head straight into a medium-intensity run. I’ve always trained by feel, and for years it worked quite well—I checked off plenty of road and trail marathons that way.

But this year, I decided to really commit to heart-rate-based training. I downloaded Matt Fitzgerald’s 50K plan into TrainingPeaks and got started. The problem? I didn’t want the structure of running five days per week, and I didn’t embrace the time based training (I want numbers, like miles!). I also didn’t truly know my zones—Garmin gave me one number, but I adjusted it to what I thought was “easy” for trail running. My self-selected Zone 2 was… not Zone 2.

Over time, I found myself annoyed with the plan because staying in the prescribed zone felt impossible. I drifted away from it entirely and went back to training intuitively: one speed session (track or hills), a couple short runs, and a long trail run each weekend. I built up to 24 miles. My 18-miler felt incredible—smooth, efficient, exactly the pace I wanted. But the 21 and 24? Brutal. They wiped me out so completely I spent the rest of the day horizontal… which doesn’t pair well with kids around.

I ultimately decided not to race the 50K. I was burnt out, under-recovered, and honestly didn’t feel like I had the punch in my system to get through it.

Enter —> Metabolic Testing

A few months later, I purchased a VO₂ max cart for The Gait Lab—and I absolutely love this addition. Understanding an athlete’s fuel metabolism is incredibly revealing. It highlights strengths, exposes under-developed systems, and gives a much clearer picture of how to train smarter.

Naturally, I tested myself right away.

The first test was after a rough travel weekend—poor sleep, poor nutrition, lots of stress—and the results reflected that. Not great. Six weeks later, after running a bit slower and adding more consistent strength training, I retested.

The results improved, but one thing stood out:

= I have one of the smallest Zone 2 ranges of anyone I’ve tested. :

My FatMax occurs around 99 bpm.
Which means:
I am now walking almost all of my Zone 2 days, with small stretches of very slow jogging.

But here’s the empowering part:
I also know exactly where my anaerobic threshold is now—and on interval days I get to push hard with intention. Those days are my favorite.

Right now I’m fully committed to trusting the process. The science—and decades of coaches—support it. And I’m already seeing improvements: I can jog a bit more at FatMax now instead of exclusively walking.

Spending time slowing down, building more muscle mass with strength training, and doing small amounts of hard training is the tried and true way of growing Zone 2 (so it doesn’t stay a walk forever = phew!)

Why Zone 2 Training Matters

Here’s what the research (and decades of endurance coaching) tell us about the benefits of Zone 2:

1. Improves aerobic capacity
   Zone 2 builds the mitochondrial engine that supports all endurance.

2. Enhances oxygen efficiency
   Especially when paired with nasal breathing, which increases CO₂ tolerance.

3. Builds movement efficiency
   Think “10,000-hour rule”—low stress, high repetition, improved economy.

4. Quiet brain = better motor learning
   Zone 2 is where the nervous system settles, allowing deeper efficiency gains. This one might be my favorite. Instead of always pushing forward: settle back into the run (or walk!) and quiet that part of the brain saying you aren’t running fast enough!

5. Improves endurance without excessive fatigue
   You can accumulate time on feet without the big recovery cost.

6. Strengthens your fat-oxidation pathways
   A major key for long-distance performance and stable energy.

7. Creates a foundation for higher-intensity work
   The better your base, the higher your ceiling.

In Summary:

Zone 2 training isn’t glamorous. It’s slow, humbling, and often uncomfortable—not physically, but mentally. But it is the foundation of nearly every high-performing endurance athlete on the planet.

Adding metabolic testing to The Gait Lab has changed the way I train, the way I coach, and the way I understand adaptation. And if you’ve ever wondered whether you’re training in the right zones—or why your long runs feel harder than they should—there’s a good chance your internal engine just needs a little attention.

Zone 2 is where that rebuilding starts. And: if we training our weaknesses, they only promise to get stronger.