Why Feedback is Your Most Important Training Metric

One of the most common questions I’m asked by runners is:

“If my plan is written well, isn’t that enough?”

It’s a fair question.

A structured training plan provides direction. At a minimum, it should outline progression, specificity, and recovery. But in ultramarathon training, performance is rarely limited by a lack of structure.

More often, it’s limited by an athlete’s ability to consistently absorb training stress and adapt to it.

And that is where feedback becomes essential.

Isn’t Training Stress Just Mileage, Vert, and Intensity?

Not entirely.

Training is stress — but so is work pressure, travel, disrupted sleep, family responsibility, and psychological load. From a physiological perspective, these stressors share common pathways: autonomic nervous system activation, hormonal responses, inflammatory signalling, and sleep disruption.

Your body does not neatly categorise stress as “running” versus “life.” It integrates all of it.

In endurance research, this cumulative burden is often described as allostatic load — the total wear and tear on the system from chronic stress exposure. When allostatic load increases, your capacity to adapt decreases.

The aerobic run that felt smooth last week may feel unusually taxing after a night of poor sleep. A speed session that previously felt controlled may feel disproportionately difficult during a stressful work period.

The session hasn’t changed.

The ecosystem has.

This is why the context surrounding a run often matters more than the run itself.

So What Kind of Feedback Actually Matters?

Not lengthy diaries. Not complex dashboards.Simple, consistent reflection.

Before a run:

• How motivated were you to train today?

• Did you feel fresh and energised?

After a run:

• How did the effort feel relative to what was prescribed?

• Where did your mind go during the session?

• Did anything feel mechanically off?

• What did you learn?

These questions take less than two minutes to answer.

Yet they provide insight into psychological readiness, pacing calibration, cognitive load, early injury signals, and overall adaptive capacity.

Subjective measures such as perceived exertion, mood state, sleep quality, and perceived fatigue have repeatedly been shown in endurance literature to detect maladaptation earlier than objective load metrics alone.

Heart rate, power, and pace tell us what happened.

Athlete perception helps explain why.

Isn’t This Overcomplicating Things?

Quite the opposite.

It simplifies decision-making.

Long-term ultramarathon performance is less about heroic weeks and more about reducing error — identifying small deviations before they become major interruptions.

Consistent feedback allows pattern recognition:

• Motivation trending down across several days?

• Routine efforts feeling disproportionately hard?

• Subtle mechanical tightness appearing on descents?

• Mental disengagement during long aerobic work?

These are not problems.

They are signals.

The goal is not constant adjustment. It is informed restraint.

When the training ecosystem is stable — sleep consistent, stress manageable, motivation high — progression is appropriate.

When the system is strained, maintaining consistency may be the greater win.

The plan provides structure. Feedback provides precision.

And precision is what sustains long-term performance gains in a sport defined by durability.

For athletes, this approach builds awareness and autonomy.

For coaches, it sharpens judgement, deepens the working bond, and provides understanding of the athlete beyond numbers alone.

Ultramarathon performance is not simply about how much training stress you can apply — but how intelligently you manage it over months and years.