How Doing Hard Things Rewires Our Brain

Written By Andy Lapteff

When I hit 500 miles of running earlier this year, I wrote about discipline: about doing hard things, building habits, and becoming someone who shows up consistently. Weeks later, I crossed 600 miles.

That extra hundred miles didn’t come from a sudden surge of motivation. It came from repetition. From showing up in the cold. From running when I didn’t feel ready. From days when staying inside sounded far more appealing than stepping out the door.

One of those days stands out.

I didn’t want to run. I argued with myself. I stalled. I tried to justify skipping. And then I went anyway.

That run turned into my fastest mile split in decades: a 7:49 opening mile on a day my mind was actively resisting the effort.

That experience wasn’t a coincidence. And it wasn’t luck.

It was neuroscience.

The Brain Region Built for Doing What You Don’t Want to Do

There is a specific region of the brain that becomes active, and over time, stronger, when we persist through discomfort and effort. It’s called the anterior mid-cingulate cortex (aMCC).

The aMCC sits within the cingulate cortex and plays a central role in:

  • persistence

  • effortful decision-making

  • pushing through discomfort

  • sustaining goal-directed behavior under stress

In a landmark paper titled “The Tenacious Brain,” neuroscientists Touroutoglou et al. describe the aMCC as a core hub for tenacity: the capacity to continue acting toward a goal despite rising costs like fatigue, discomfort, or frustration.

“The anterior mid-cingulate cortex performs cost–benefit computations necessary for persistence and effortful behavior.”
— Touroutoglou et al., Cortex, 2020
https://pmc.ncbi.nlm.nih.gov/articles/PMC7381101/

In plain terms:
When your brain asks, “Is this worth continuing?” — the aMCC helps answer that question.

And here’s the key insight:

The aMCC adapts to use.

Doing Hard Things Trains the aMCC

Research suggests that people who regularly engage in effortful, goal-directed behavior show stronger structure and function in the aMCC compared to those who avoid effort when it becomes uncomfortable.

This idea was popularized outside academic journals by Andrew Huberman in his conversation with David Goggins, where Huberman explains that doing things you don’t want to do is one of the most reliable ways to strengthen this brain region.

“When you force yourself to do things you really don’t want to do, you are engaging and potentially strengthening the anterior mid-cingulate cortex.”
— Andrew Huberman, Huberman Lab Podcast (with David Goggins)
https://www.hubermanlab.com/episode/david-goggins-how-to-build-immense-inner-strength

Importantly, this effect is not driven by enjoyment.

The aMCC is not trained when the task feels easy, pleasurable, or motivating.
It is trained when there is resistance: when the brain must overcome an internal signal to stop.

That distinction matters.

Why the Hardest Days Matter Most

From a brain-training perspective, not all effort is equal.

  • Running on days you want to run builds fitness.

  • Running on days you don’t want to run builds tenacity circuitry.

The aMCC is most active when there is a mismatch between desire and action: when you act despite an internal signal telling you not to.

That’s why my fastest split didn’t happen on a day I felt energized or inspired.

It happened on a day when my aMCC was forced to do real work.

After hundreds of prior runs, many of them uncomfortable, inconvenient, or unwanted, the neural circuits responsible for persistence were no longer fragile. They were practiced. Efficient. Reliable.

That run was not motivation showing up.

It was a trained brain doing what it had learned to do.

Repetition Changes the Brain, Not Motivation

The aMCC follows the same principle as muscle tissue: use-dependent plasticity.

Repeated activation leads to:

  • stronger synaptic connections

  • improved efficiency

  • increased baseline readiness to engage effort

This is not speculative. Structural and functional brain imaging studies consistently show that effortful behavior changes neural organization over time.

Touroutoglou and colleagues describe this as the brain learning to treat persistence as a default rather than an exception.

“Tenacity emerges from repeated engagement of neural systems that evaluate effort costs and sustain action over time.”
— Touroutoglou et al., 2020
https://pmc.ncbi.nlm.nih.gov/articles/PMC7381101/

In other words: The more often you do the hard thing, the less dramatic it feels to do it again.

Why This Applies To Everything

Exercise is a simple, repeatable way to expose the aMCC to effort.

But the same circuitry is involved when you:

  • sit down to work when you’d rather scroll

  • study when you feel mentally tired

  • have a difficult conversation instead of avoiding it

  • stick with a long-term goal when progress feels slow

The brain does not distinguish between “physical” and “mental” effort at this level.
It distinguishes between effort and avoidance.

Train one, and you influence the other.

The 600-Mile Lesson

That hundred miles between 500 and 600 weren’t about endurance.

They were about repetition in the face of resistance.

Each time I ran when I didn’t want to, I was reinforcing a simple neurological message:

We do not stop when things are hard.

Over time, that message became embedded in circuitry.

That’s what showed up in that 7:49 mile.
Not willpower.
Not hype.
Not motivation.

A trained anterior mid-cingulate cortex.

Doing the Hard Thing Makes You Better: Literally

We often talk about discipline as a character trait.

Neuroscience suggests it’s also a trainable biological capacity.

Doing hard things you don’t want to do:

  • strengthens the aMCC

  • improves persistence under stress

  • reduces reliance on motivation

  • increases follow-through across domains

This is why the hardest days matter most.
They are the days when our brain changes.

Running is where I practice this, but the benefits show up everywhere.

Not because I feel tougher.
Because my brain is.

References & Further Reading

Andy Lapteff
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