It Was Already Slipping Much Earlier
Most marathon failures are described as late events.
“Everything was fine until the last few kilometers.”
“The wall came out of nowhere.”
“I just ran out of energy.”
But marathons rarely fall apart suddenly.
They unravel.
And they almost always start unraveling long before the point where it becomes visible.
The final kilometers are not where the problem begins.
They are where it becomes impossible to hide.
Up to that point, the body can compensate. Pace can be held with slightly worse mechanics. Fatigue can be absorbed by coordination, focus, and habit. Small inefficiencies don’t immediately feel like errors. They feel like “normal marathon fatigue.”
But compensation has a cost.
And that cost accumulates quietly.
This is why many runners experience a very specific kind of race:
controlled, steady, even reassuring — until it isn’t.
Nothing dramatic happens at first. The pace drifts by a few seconds. Form becomes a little more rigid. The effort required to maintain rhythm increases, but not enough to trigger alarm. The runner adapts without realizing it.
By the time the final kilometers arrive, the system is already operating near its limit.
What looks like a late collapse is usually the exposure of a long-standing imbalance.
A large part of this comes from how training is structured.
Many runners build excellent aerobic bases. High volume. Clean Zone 2 work. Well-managed weeks. Consistency without chaos. This kind of training is effective — but only within the conditions it prepares for.
Zone 2 teaches the body to work efficiently when the system is fresh and stable.
The marathon’s final phase is neither.
After thirty kilometers, the problem is no longer aerobic capacity alone. It is mechanical resilience. The ability to keep moving well when muscles are already damaged, coordination is degraded, and every step costs more than it did before.
If training never asks the body to operate under those conditions, the adaptation simply doesn’t exist.
The same logic applies to long runs.
Running long in comfort builds durability, but it does not automatically build resistance to late-stage fatigue. When long runs always end before they become structurally challenging, they teach the body one thing very well: how to stop before it matters.
This is not a question of toughness.
It is a question of exposure.
The body adapts to what it is asked to handle — not to what is avoided politely.
Nutrition often gets blamed for what happens at the end of a marathon. Sometimes rightly. Often not.
Fuel supports performance, but it cannot compensate for rising mechanical cost. When movement becomes inefficient, energy drains faster regardless of intake. This is why runners can “eat correctly” and still slow down.
The issue is not always how much fuel is available.
It is how expensive each step has become.
Understanding this shifts the focus away from last-minute fixes.
The solution is rarely found in a better gel, a different pacing trick, or a more aggressive mindset. It is found in how training prepares the runner to stay functional when conditions degrade.
Not comfortable.
Functional.
This is the core idea explored in Fino al km 38 andava tutto bene.
The book is not about optimizing splits or chasing perfect plans. It is about learning how and why performance degrades — and how training choices quietly determine when that degradation begins.
The collapse at the end of a marathon is rarely the cause.
It is the consequence.
You can find the book here:
https://a.co/d/678Qvyn