Get in the Zone. The Aerobic Zone.
- Aidan Malody
- 2 days ago
- 8 min read
If you’ve been around fitness long enough, you’ve definitely heard someone say:
“I kept it easy, so it was Zone 2.”
“I could talk, so it was Zone 2.”
“I was nasal breathing… so Zone 2.”
Cute.
Also: usually wrong.
Zone 2 has become one of those fitness buzzwords that sounds simple but is almost never done correctly. Not because people don’t care — but because most folks try to identify Zone 2 by feel. And feel is one of the least reliable ways to measure something that’s fundamentally physiological.
This guide breaks down what Zone 2 actually is, why your feelings lie, how to measure it without needing a lab coat, and how it helps you become a better CrossFit athlete, a better HYROX athlete, and a more capable human overall.
What Zone 2 Actually Is
This is the part everyone thinks they understand — until they don’t.
Zone 2 isn’t defined by:
How easy it feels
Whether you could hold the pace “forever”
Whether you can breathe through your nose
Those are sensations — not measurements. They may show up during Zone 2, but they don’t identify Zone 2.
Zone 2 is a physiological intensity where your body is still primarily using aerobic metabolism: burning fat efficiently, producing energy steadily, and keeping fatigue low. Cross the line, and you’re no longer in Zone 2, even if everything “feels” fine.
It usually lines up with:
~60–70% of your true HRmax
~65–75% of your VO₂max
Just below your first lactate threshold (LT1)
Below your Critical Power (CP)
Blood lactate around ~2.0 mmol/L
Takeaway: Zone 2 isn’t a pace — it’s a metabolic neighborhood.
Why Feelings Lie
Your perception of “easy” often has nothing to do with your physiology.
Examples you’ve 100% lived:
You feel relaxed… but your heart rate is basically waiting at the DMV… before they even open.
You can hold a conversation… while your lactate is quietly climbing.
You can nasal breathe… but only because you have elite airways.
And then you have people like me — someone blessed with the nasal capacity of a decorative candleholder. I can barely breathe through my nose even at rest. One nostril is basically there for aesthetics.
But here’s the part most people don’t realize:
Fitness level and pain tolerance distort perception just as much as inexperience.
Some people have built years of CrossFit discomfort tolerance. They can be deep in Zone 3 or 4, heart rate spiking, lactate climbing… and still say, “I feel pretty good.” They’re not lying — they just have a big redline window and a high “this is fine” threshold.
On the flip side, some people are brand new or detrained. Their internal alarm system fires the second anything feels mildly unpleasant. Zone 2 to them feels like Zone 4. These are the people who get a paper cut and react like they need a helicopter evac.
Neither scenario means anyone is actually in Zone 2.
This is why “feel,” “easy,” “talk test,” and “nasal breathing” cannot be used to determine Zone 2.
The point: Use these cues to monitor effort — not to determine your zone.
If Zone 2 were based on vibes alone, half of us would hit it the moment we start gossiping on a BikeErg like we’re waiting for our hair to dry at a salon. Unfortunately, your mitochondria don’t care about your tea.
How to Find Your Real Zone 2
Here are the methods that actually work — not guesses, vibes, or hope.
There are several scientifically validated ways to identify Zone 2. Some require testing, some require effort, none require guessing.
Heart Rate Method
Zone 2 corresponds to ~60–70% of your actual HRmax.
The catch? Your wearable doesn’t know your HRmax. The “220 − age” formula is a meme that refuses to die, and even two 35-year-olds can have max heart rates of 176 and 205. That’s a massive spread — and a massive difference in what Zone 2 would be.
However...
Wearables are good at one thing: Measuring your current heart rate.
What they’re not good at is predicting your max.
Even if your watch sees a heart-rate spike during a workout, most devices won’t automatically update your HRmax. Wrist sensors can jump due to motion noise, and companies don’t want accidental spikes resetting your training zones.
And heart-rate spikes happen for all kinds of reasons that have nothing to do with fitness — your friend jump-scares you, you get bad news, you almost drop a barbell on your foot, or you let out a loud fart at the bottom of a squat just as the music cuts out in the middle of class. These spikes show up on your watch, but they’re not your true max effort — they’re just life happening aggressively.
Meaning: your device might record your highest heart rate, but it won’t assume it’s your true max unless you go in and set it manually.
Important note:
If heart rate is the only method you’re realistically going to use, that’s totally fine — just understand it’s a broader estimate, not a precision tool. You’ll get close, but not exact.
So if you’re going to use heart rate, give your wearable a fighting chance by feeding it the right data.
Simple HRmax Test
Warm up 8–10 minutes. Then perform:
90 seconds hard → rest 60–90 seconds
90 seconds harder → rest 60–90 seconds
60 seconds very hard → rest 45–60 seconds
30 seconds all-out → note the highest HR you see
That number = your HRmax. Now your Zone 2 HR range is accurate.
Takeaway: HR works beautifully — but only if you feed it real data.
Lactate Testing
Zone 2 occurs around ~2.0 mmol/L of lactate.
Lactate itself isn’t the enemy — it’s just a marker showing when your body begins shifting away from pure aerobic metabolism.
It is extremely accurate. It is also extremely “poke your own finger repeatedly.”
Most athletes don’t need to live this life unless they love spreadsheets and pain.
Critical Power (CP)
This is hands-down the best real-world method for most athletes.
Critical Power = the highest output (watts or pace) your body can sustain aerobically. Zone 2 often sits around 60–80% of CP.
Why CP is awesome:
It’s individualized
It uses watts or pace (no HR drift)
It’s amazingly consistent
It’s practical for CrossFit and HYROX athletes
It gives you real training targets, not guesswork
The CP Test
On the same machine (rower, SkiErg, Echo Bike, treadmill):
3-minute max effort → record average watts
Rest 10–15 minutes (easy walking/spinning, nothing intense)
8-minute hard effort → record average watts
Plug into the validated Monod–Scherrer model:
CP = (P₈ × 480 − P₃ × 180) / 300
Where:
P₃ = average watts from 3-minute test
P₈ = average watts from 8-minute test
This gives your CP.
Plain language:
Watts show up on the screen during the CP test, but that doesn’t make it a “performance test.” Watts are simply the cleanest, most objective way to measure how much steady work your aerobic system can actually sustain. You can’t fake 8 minutes of output with hype, and the equation removes your anaerobic burst anyway. What’s left is your true aerobic ceiling.
We measure watts, monitor heart rate, and use both to determine your Zone 2 with confidence.
Takeaway: CP = output. HR = internal response. Together = accuracy.
How to Combine CP and Heart Rate
This is the gold standard if you want near-lab accuracy without an actual lab.
Step 1: Do the CP Test
3-minute max effort
Rest 10-15 minutes
8-minute hard effort
Record average watts for both intervals.
Step 2: Calculate Your CP
Use the equation above. You now have your Critical Power.
Step 3: Find Your Zone 2 Watts
Zone 2 = 60–80% of CP (Closer to 60% if you’re newer; closer to 70–80% if trained.)
Step 4: Use Heart Rate as the Internal Check
While holding your Zone 2 wattage:
Your heart rate should land near 60–70% of HRmax
Breathing should stay stable
You should be able to talk in short phrases
If HR spikes way above your range → watts too high. If HR won’t rise into the range → your engine is underdeveloped (normal!), stay at the watt target and let HR catch up over time.
Step 5: If CP and HR Don’t Match (This Happens Early On)
Trust watts as your anchor. Let HR drift naturally. Over 3–5 weeks, HR will begin aligning with the correct Zone 2 wattage as your aerobic system adapts.
Takeaway: CP gives you the true external intensity. Heart rate shows the internal adaptation over time. Together, they’re unmatched.
Talk Test / Nasal Breathing
These should never be used to find your Zone 2.
But after you identify your true Zone 2?
Yes — these sensations start to make sense.
Breathing stays stable
Talking in short phrases is easy
Pace feels… boringly sustainable
These are confirmations — not measurement tools.
Why Zone 2 Matters
Zone 2 builds the engine behind everything you do in fitness. Not the glamorous engine — the real engine. The one that keeps you from melting halfway through a workout.
Better Energy Production
Zone 2 increases mitochondrial density — your body’s cellular engines.
More mitochondria = More energy → Better endurance → Better recovery → Less panic breathing mid-workout.
Improved Fat Oxidation
Zone 2 teaches your body to rely on fat longer before switching to high-cost carbohydrate metabolism.
This means you stop redlining early when:
Running between HYROX stations
Hanging on to longer CrossFit intervals
Grinding through EMOMs
Better Repeatability
Zone 2 improves your ability to repeat effort without massive performance drop-offs.
Translation: You stop dying in round 2 of anything.
CrossFit Feels More Manageable
Zone 2 helps regulate:
Pacing
Transitions
Heart rate
Recovery mid-workout
Your heart won’t spike uncontrollably every time you pick up a barbell.
HYROX Requires Aerobic Control
HYROX is a long aerobic event disguised as a strength race.
Zone 2 supports:
Consistent running
Steady station output
Recovering between sleds and burpee broad jumps
Not spiritually exiting your body on the last two runs
Better Health and Longevity
Zone 2 improves:
Resting heart rate
HRV
Blood sugar regulation
Cardiovascular health
Stress tolerance
Daily energy levels
It makes you better at workouts and life.
How to Use Zone 2
You don’t need to train Zone 2 four days a week — not unless you’re rebuilding your engine from scratch.
Instead, Zone 2 is perfect when:
You burn out early in workouts
You can’t pace
You feel like your aerobic base is lagging
You want more training volume without frying yourself
You don’t have the energy for intensity but still want to move
You’re newer and developing athlete awareness
You’re training for HYROX or any longer CrossFit event
Zone 2 fits beautifully on:
Active recovery days
After strength sessions
Low-intensity conditioning days
“I want to move but not die” days
It’s not replacing your training —it’s supporting all of your training.
The Quiet Work That Makes the Loud Work Possible
Zone 2 is funny because it looks boring until you realize it’s the thing you’ve been missing. I used to skip it, too — because who wants to go “slow” when you could sweat harder and feel tougher? But once you train it correctly, everything gets easier: pacing, breathing, transitions, even your confidence. It’s the quiet work that makes the loud work possible. Build your engine, trust the process, and let the rest of your training finally breathe a little easier.
Stay Dope.