If you’ve started training for a half marathon or marathon and your plan says something like:

“Keep most of your runs in Zone 2”

…you might be feeling confused or frustrated.

Maybe your heart rate shoots up even at a slow pace.
Maybe you keep having to walk.
Maybe you’re thinking, “Am I just really out of shape?”

Let’s clear something up right away:

👉 Struggling to stay in Zone 2 is extremely common — and it’s not a personal failure.

And in many cases, it’s not just about fitness.

What Zone 2 is supposed to feel like

Zone 2 running is meant to:

• Feel easy and conversational
• Build your aerobic base
• Teach your body to use fat efficiently
• Lay the foundation for long-distance endurance

It’s not supposed to feel like a constant fight to keep your heart rate down.

If it does feel like a fight, your body may be under more stress than you realize.

Why your heart rate might be climbing so fast

There are a few common reasons Zone 2 feels hard:

• You’re newer to endurance training
• You’re training in heat or humidity
• You’re not sleeping well or feeling stressed
• You’re under fueling (this one is huge)

That last one often gets overlooked.

How under fueling affects your heart rate

When your body doesn’t have enough fuel, it doesn’t quietly adapt — it stresses.

That stress shows up as:

• A higher heart rate at easier paces
• Feeling “out of breath” sooner
• Runs that feel harder than they should
• Needing walk breaks even when you’re moving slowly

This can happen if you:

• Skip meals
• Train on coffee alone
• Eat very low carb during base training
• Are unintentionally in a calorie deficit

Your body interprets low fuel as a threat — and heart rate goes up to compensate.

A really important myth to bust

Many runners think:

“If I fuel less, I’ll burn more fat.”

But here’s the truth:

👉 You don’t improve fat burning by stressing your system.

Fat-burning improves when:

• Your aerobic system is supported
• Stress hormones stay lower
• Blood sugar is stable
• Your body feels safe enough to adapt

When fuel is too low, your body relies on stress hormones instead of efficiency — and Zone 2 becomes harder, not easier.

How better fueling can actually make Zone 2 easier

Fueling well doesn’t mean:

• eating constantly
• overdoing sugar
• or “ruining” aerobic training

It means:

• Giving your body enough energy to stay calm
• Supporting the work you’re asking it to do
• Letting your heart rate stay lower at the same pace

Many runners notice that when fueling improves:

• They can run longer before HR drifts up
• Walk breaks become less frequent
• Easy runs feel more relaxed
• Zone 2 finally starts to feel… easy

Does this mean you need carbs for every easy run?

Not necessarily.

But it does mean:

• Your overall daily intake matters
• Skipping meals hurts more than skipping mid-run fuel
• Base training still requires energy
• Long runs and higher mileage weeks need support

You can’t build an aerobic engine while running on empty.

About walking during Zone 2

Walking is not a failure.

Especially early in training:

• Walking helps keep effort where it should be
• It protects the aerobic system
• It prevents turning easy runs into hard ones

But if you’re walking constantly and feeling discouraged, it’s worth looking at fueling, not just pace.

What to tell yourself if you’re frustrated

Instead of:

“I’m bad at Zone 2”

Try:

“My body might need more support right now.”

Zone 2 is a skill.
Efficiency takes time.
Fueling is part of the training — not a shortcut around it.

The big takeaway

Zone 2 training works best when:

• The pace is appropriate
• Stress is managed
• Fuel availability supports adaptation

You can’t train your aerobic system if your body is stuck in survival mode.

If Zone 2 feels impossible right now, you’re not broken — your system is just asking for support.

And that’s something you can fix.

If this sounds like you…

If you’re:

• Training for a half marathon or marathon
• Struggling with Zone 2 despite “doing everything right”
• Curious how nutrition can support aerobic fitness instead of fighting it

I’d love to help you.
You don’t need to feel discouraged every time your watch beeps.

📩 Reach out anytime — we can build a plan that supports your training, your metabolism, and your long-term enjoyment of running.

Because running should feel challenging at times — not constantly frustrating.

Always in your corner,

Coach Misty