What factors determine athletic performance? (Series 1: Energy systems)

My friends from 42K I have been challenged to regularly produce content on endurance race training, applicable to all levels.

The idea behind this section is clear: through short texts—which we will call series— we will address Practical applications of core trainingredresistance ors based on my professional experience, without neglecting the academic rigor that inevitably accompanies me.

I don't intend to discover the Fierabrás's balm There's no secret formula for athletic performance here. In many cases, what you'll read will reinforce what you're already doing. In others, it might help you make adjustments to make your training sessions more efficient. This isn't about questioning the work of other professionals either: athletic performance can be achieved in many different ways. I'll be talking about what I believe works for me.

While I receive proposals on specific topics - I encourage you to submit them in the comments - I will begin by answering a fundamental question:

What factors determine athletic performance?

We could find multiple answers, approaches, and nuances when addressing the question of the factors that influence athletic performance. However, from my point of view, the success of sports training rests primarily on two main pillars:

• The test profile
• The athlete's profile

In this first series we will focus on the first one.

Series 1: Energy System Contributions

The test determines the physiological demands

If we're talking about improving our athletic performance over a specific distance, it's clear that the needs of a 5K are not the same as those of a marathon.

Physiological demands depend primarily on one factor: the duration of the effort.

To the point that, in terms of energy metabolism, a cyclist seeking to break the hour record will use metabolic pathways similar to those of a half-marathon specialist, since both efforts are around 60 minutes in duration.

In other words, different disciplines can share similar energy demands if the effort time is comparable.

What are energy systems and why do they matter?

If you search for the term “energy system contributions” You'll find plenty of scientific literature analyzing how different energy systems contribute depending on the duration and intensity of exercise. That's what I did to develop the theoretical framework for my doctoral thesis.

Our organization has, to put it simply, three major energy production systems:

• Anaerobic alactic system (very brief and explosive efforts)
• Anaerobic lactic system (high intensity, short-medium duration)
• Aerobic system (prolonged efforts)

In endurance races, the aerobic system clearly plays a leading role. However, the other systems don't disappear: they contribute at specific moments such as changes of pace, steep climbs, or final sprints.

The fuel tank analogy

We can imagine the body as a vehicle with several fuel tanks.

The training aims to optimize:

• The capacity of each tank.
• The efficiency with which we each use one.
• The transition between them.
• Resistance to fatigue when the dominant system begins to exhaust itself.

If we use all our "storage" at maximum intensity from the start, we can sustain that effort for a limited period. After that, fatigue will appear prematurely and performance will drop. Therefore, that strategy will only make sense for short-duration endurance races (mid-distance).

However, if we properly manage which energy system...redBy monitoring the payroll at all times, we can sustain performance for a longer period.

The route also modifies energy demands

In long-distance road races, we often look for flat routes to optimize our final time. But why is this?

A flat course allows for a more stable intensity, which promotes greater efficiency of the aerobic system.

In contrast, in trail running tests running or cross-country:

• The climbs increase the anaerobic demand.
• Downhills modify muscle pattern and energy cost.
• Constant variations disrupt metabolic stability.

This implies that, even while maintaining the same total duration, the relative contribution of energy systems changes according to the orography.

Duration + route profile = strategy

When we combine:

• Duration of effort
• Intensity
• Terrain profile

An essential concept emerges in endurance performance:

Pacing (rhythm distribution)

El pacing It's not simply about "starting slower"; it's about the ability to strategically distribute effort to:

• Optimize the use of energy systems.
• Delay the onset of fatigue.
• Maximize final performance.

We could say that, a bad pacing It involves prematurely activating less efficient energy systems for prolonged efforts.

A good pacing It means understanding what the test demands and adapting the energy strategy from the first kilometer.

In the following a series of We will address this concept in depth and connect it with energy contribution systems.

Conclusion: understand before intervening

Athletic performance does not depend solely on training more or training harder.

Actually, it depends on understanding the following:

• What the test requires.
• What energy systems predominan.
• How the duration of the effort influences it.
• How the terrain modifies physiological demand.

Ultimately, training with intention involves understanding the energetic context of the effort.

If you're interested in delving deeper into the factors that determine athletic performance, I invite you to the next series.

“Running is easy; training with intention is another story.”

Text to 42K of :

Toni Montoya Vieco

CD Metaesport Technical Director

National Athletics Coach and Doctor of Physical Activity Sciences
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