The Wicked Relationship Between Training Volume and Performance.

Do athletes improve because they train more, or do they train more because they improve?

One of the (few) things that seems to garner consensus among professionals in Sports Science is the necessity of training many hours to become a professional athlete in endurance sports.

Although high training volumes often do not outperform higher-intensity interventions (intervals) in intervention studies, all observational studies show that the highest-level athletes are characterized by training more hours than lower-level athletes.

There are many reasons why this could happen, with the main one, in my opinion, being that intervention studies are too short to allow the benefits of low-intensity training to emerge in comparison to high-intensity training.

However, what drives me to write this article is to go beyond the current interpretations. We could settle for the idea that the more we train, the better, and that to become professionals, we must train many hours.

That would be a treat for our certainty-craving brains, sparing us many headaches. But some people are not satisfied with slogans and want to understand the "why" behind things, even if it means walking a path of uncertainty and frustration. These are the people who want to go a step further and choose to read this newsletter instead of relying on the simple slogans and answers found on social media.

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Today, this study, led by researcher Dani Muñiz (whom I had the fortune to interview on my podcast, in Spanish), was published. The study is fantastic because it uses data from numerous athletes on Strava, analyzing the relationship between their marathon times and their training methods. Specifically, it examines the relationship between marathon time, which reflects the athlete’s level, and the total training volume. Moreover, it analyzes whether this training is performed below the first threshold (moderate domain, white and green zones), between the two thresholds (heavy domain, yellow zone), or above the second threshold (high intensity, severe domain, red and purple zones). This is measured using speed, estimating each athlete’s Critical Speed and the first threshold at 82.5% of their Critical Speed.

There were already many prior studies (link), (book chapter)… showing how professional and elite athletes train more hours, but this one stands out for analyzing a large number of athletes and because it gave me the idea to write this article. I do not write this as a critique, far from it, but to provide context to these findings because I believe people are taking away the overly simplistic message that "to improve, you must train a lot," and that is inaccurate.

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Everyone seems to assume that the way to become a professional and improve is by training many hours. But is it really that simple?

I always say that if, as a cyclist, I realized that training more would make me faster, I would train 20 hours a day. After all, training is what endurance athletes love the most, especially at a low pace. On top of that, you're burning calories and staying away from the fridge.

But what’s the limit? If the best are the best because they train more, why not train even more?

Sometimes, we are told that great champions are great because they can train more than others, as if everyone else were lazy. When in reality, it’s the opposite: they can train more because they have a higher level.

Notice how it’s actually an inverse relationship. You train more because you have a higher level.

Ultimately, the most important thing for long-term improvement is not training a lot on some days but training consistently over many years.

And the ONLY way to train a lot over many years is by balancing the load you place on your body with its recovery capabilities.

You could try training like a professional, but if you can’t recover like a professional, you’ll manage one or two strong months before you have to stop. First, your performance will plummet, and then your health will follow.

The key to athletic development is balancing the stimulus and recovery so that you don’t get so fatigued that you fall ill or lose months of progress due to breaks, while maintaining a continuous stimulus that forces your body to express the epigenetic adaptations needed to reach your athletic potential.

And this training dose is obviously very different for a beginner compared to a professional.

But there are also other factors that affect the number of training hours.

First, let me clarify that total volume is a very poor metric for measuring training load. As I explain in my book, the stimulus depends on the type of stimulus (which physiological structures are affected by the training) and its magnitude (the degree of stress applied, which depends on the volume, intensity, and frequency of the stimulus).

Thus, we could provide an equivalent stimulus to the body with more hours at a lower intensity or fewer weekly hours at a slightly higher intensity. At first glance, it’s impossible to say that doing 30 hours in the white zone is harder than doing 15 hours in the green zone or 5 hours in the yellow zone (zones explanation).

Professional athletes tend to do more volume at low intensity for several reasons:

• They have more free time—or all the time in the world—so they can achieve the stimulus with more volume and lower intensity. On the other hand, amateurs with limited time due to work need to reach the same stimulus by training harder.

• They have a higher level, allowing them to stay longer in low zones. An amateur or untrained athlete may unintentionally be in the heavy domain (yellow zone) just by running. This is also common in cycling, where low-level cyclists struggle to climb a hill without reaching heart rates in the yellow or red zones.

Notice, it’s not that training longer at low intensity necessarily improves performance; rather, the chosen way to improve performance is low intensity.

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To conclude, my recommendation for you is to adjust the intensity to the time you have available.

If you have plenty of time to train, there are advantages to doing high volumes at lower intensities.

• The lower the intensity, the less activation of the sympathetic system, and therefore less production of hormones like cortisol, adrenaline, and others that, when chronically elevated, cause fatigue, catabolism, etc.

• The lower the intensity, the less muscle damage due to contracting fewer muscle fibers, as less force is needed.

• The lower the intensity, the lower the mental load and the greater the adherence. You can talk, enjoy the scenery, and think.

• The greater the volume, the higher the calorie and fat expenditure, helping you maintain your weight.

Above all, the most relevant aspect is that humans have evolved with the need to perform several hours of low-intensity exercise daily. This activity was done at a pace that we wouldn’t even consider training (walking, manual labor, etc.), but it’s work we can do daily, in various nutritional states, without leading to exhaustion.

This is mainly why working at low intensities generates less fatigue. Although Christopher McDougall titled his book Born to Run, in reality, homo sapiens were "born to walk."

At the same time, this evolutionary adaptation explains why, for a well-trained athlete, walking or light exercise is such a low-level stimulus if the goal is to improve performance. Adaptation is an energetically costly process, and the body will only adapt if the stimulus is strong or chronic enough that being well-adapted becomes more efficient than not being adapted.

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Therefore, there are certain advantages to working at low intensities and high volumes when you have unlimited time, but this only matters if you have enough time to generate all the training load you can recover from.

On the other hand, if you’re a “weekend warrior” with limited time to train, you can achieve the same stimulus by training less but harder, and you shouldn’t worry too much about fatigue.

If you have limited training hours, you shouldn’t follow the training recipes of top endurance champions but instead a plan tailored to you.

Also, don’t make the mistake of trying to train more at all costs by sacrificing your work, family, or rest time. Over weeks or months, you’ll pay the price.

And let me tell you in advance: it’s more important for you to be well and at peace, with your life in order, than to try squeezing in 3 or 4 extra training hours per week, only for everything to fall apart in the long run.

I won’t stop repeating this because it’s hard for us to grasp: context is the most important thing. You are you and no one else. Make the training fit you because there are many paths to success, and the more we learn, the more we realize that training well is much easier than we’re led to believe—and probably why so many people train poorly.

Context is the most important thing. You are you and no one else. Ddon’t make the mistake of trying to train more at all costs by sacrificing your work, family, or rest time. Over weeks or months, you’ll pay the price.

P.S. Why do I insist so much on you reading my book?

Because I wrote this article in half an hour, but it took me a whole year to write the book.

I would love for athletes to engage with what I put the most effort into creating.

Without the book, I’m just another person sharing their opinion. However, in the book, I strive to help you understand the deeper "whys" behind all the important questions and answers we need to address as athletes, coaches, and/or sports scientists.