Are Long-Distance Runs Really Dangerous for Children?

What Sports Medicine Says — and What My Own Experience Tells Me

A few days ago, I received a message from a journalist from Slovenske novice, asking whether I could give a professional opinion on children running longer distances. The question arose after the organizers of the Three Hearts Marathon in Radenci prevented an 11-year-old boy from participating in the half marathon.

The boy had been preparing for the race with great dedication and would undoubtedly have been capable of completing the 21-kilometre distance. After all, earlier this year he finished the Small Karst Marathon in Sežana in a time of 1 hour and 37 minutes.

Children are different, and what matters most is a healthy and sensible approach.

So do I support children running longer distances or not?

At first glance, the question seems simple. But if we truly want to stand behind the answer from different perspectives, we quickly realize that it cannot be answered with a simple yes or no.

I also understand the organizers of running events. They operate within their own rules, recommendations, insurance policies, and legal responsibilities. If a serious medical complication were to occur, they would be the first to face the consequences. And yet, I sometimes wonder whether a date of birth is always the best — or the only — criterion.

When we talk about children and sport, we often want clear answers. Black or white. Safe or dangerous. Allowed or forbidden. But the human body — including a child’s body — is not the same from one person to another. And life does not function according to a rulebook where one number could determine what is right for every child.

In my experience, the real issue is usually not the distance itself, but the approach. My own son completed 21 kilometres at the age of nine. Not as a competition against others, but as a gradual, calm, and supervised experience of movement, where running and walking naturally complemented each other. The most important thing was not that he completed a certain distance, but that he learned to listen to his body, adjust his pace, and understand that it is always acceptable to slow down or start walking.

What matters, then, is how a child runs: at what pace, how gradually they progress, whether they can adapt to weather conditions, whether they know how to listen to their body, and whether they are able to stop in time if pain or excessive fatigue appears.

Is It Healthy for the Heart?

If we first look at the cardiovascular aspect — the one that tends to frighten people the most — we actually do not have particularly strong evidence to justify major fear. In healthy children, the risk of serious cardiovascular complications during running is very small, although not entirely nonexistent (1).

What matters most is:

• that the child has no symptoms such as chest pain, fainting, unusual shortness of breath, or heart palpitations,

• that they do not run while sick or shortly after a viral infection,

• that the training load progresses gradually,

• and that we are able to distinguish between healthy exertion and excessive strain.

Overheating or Dehydration?

During long runs, overheating is often a much more realistic risk than dehydration itself. Yet many people misunderstand this and too quickly associate the problem mainly with dehydration. Such oversimplification can be misleading. Symptoms such as dizziness, nausea, headache, or fatigue are often immediately attributed to dehydration, even though the main issue may actually be the accumulation of heat in the body due to excessive intensity, high temperatures, or an inappropriate pace.

When it comes to overheating, the greatest problem is often not the child’s physiology itself, but rather inexperience. In other words, children are not necessarily more prone to overheating; the problem is mainly that they do not yet know how to respond properly to the early signs of overheating (2).

A child often cannot yet recognize the warning signs in time or adjust their behaviour appropriately — for example by consciously slowing down, starting to walk, pouring water over themselves, or even stopping the run altogether. This is why the presence of an experienced adult during longer runs is extremely important. An experienced adult can monitor the child’s condition and react in time. Of course, children are not the only inexperienced ones — adult recreational runners often make similar mistakes.

Naturally, it is important that a child has regular access to fluids. However, modern sports medicine increasingly points out that, in most healthy people, thirst is often quite a reliable signal of the body’s need for fluids (3).

It is also interesting how differently we view prolonged exertion in different sports. In cycling, hiking, or cross-country skiing, several hours of activity for children often seem far more acceptable than in running. Perhaps this is because we intuitively understand something important: the duration of movement alone is not necessarily the problem. What matters most is how intense, how gradual, and how controlled the effort is.

What About Growth Plates?

It is also interesting that concerns about overloading growth plates are most often mentioned in connection with long-distance running, even though sports medicine regularly observes similar issues in sports such as football, basketball, gymnastics, jumping events, and other activities involving explosive forces, repeated impacts, and rapid changes of direction. In such sports, the forces acting on joints and growth plates can often be even greater than during calm endurance running (4).

And yet, in these sports we generally do not impose age restrictions on participation itself. And let there be no misunderstanding — I am not suggesting that we should introduce them. Quite the opposite. This mainly shows that the key issue is a healthy approach to movement, not merely the number of kilometres.

What About Psychological Resilience?

I also believe that in endurance sports we often forget another very important aspect — psychological resilience.

Running, hiking, cycling, and other endurance activities do not only teach us how to move; they also teach us how to relate to effort. They teach us that we can observe fatigue without panic. That we can adjust our pace. That sometimes we can slow down, take a breath, and continue. And that discomfort does not necessarily mean danger.

These are not important lessons only for sport, but for life as well.

One month before my fifteenth birthday, I took part in a run from Celje to Logarska Valley. The distance was 73 kilometres. The start was at one o’clock in the morning, but my brother Primož — who had just turned eighteen at the time — and I missed it, so we joined the runners in Levec and shortened the route by approximately four kilometres.

I still remember that run vividly today. Not because of the result. Not because of the time. But because of the feeling that I was capable of persevering even when things became difficult.

That experience became part of who I am.

Of course, this does not mean that children should be running ultra-long distances en masse. But it does mean that thoughtfully guided endurance experiences can have important psychological value. They can help develop patience, self-confidence, a sense of personal capability, and a healthier relationship with stress.

Perhaps this is one of the greatest values of endurance sports — that they teach us how to remain calm even when things become difficult.

Running Is Not Just Competition

There is another interesting point that often comes to mind. Children’s races are usually short, yet children often run them almost entirely “all-out.” Precisely because of this very high intensity, such races can sometimes be physically and psychologically more demanding than a somewhat longer distance run at a calmer pace — where a child could gradually learn to listen to their body, adjust their effort, and also enjoy movement itself.

That is exactly why, in Bohinj on Saturday, June 6th, we will organize children’s runs a little differently. The children will run approximately one kilometre, but not with the main goal of finding out who is the fastest. Instead, the focus will be on a different question: how can we enjoy running more? Jasmina and I will lead the runs together.

After the children’s runs, we will also hold a free one-hour running workshop for adults — yes, including parents — where we will explore key approaches to enjoying running more and experiencing physical effort in a calmer and more relaxed way.

Some eleven-year-olds spend most of their day in front of screens. Others regularly hike in the mountains, run, cycle, and gradually develop endurance. The differences between them can be enormous.

And that is precisely why I believe it would make sense to think about more flexible possibilities. A child could participate in longer races while being accompanied by a parent or another responsible and experienced adult who would know how to guide the child through the run in a way that makes the experience positive and encouraging for the future.

Because the goal of children’s sport is probably not to create a ten-year-old marathon runner. The goal is something far more important. Something far more lasting.

That a child does not begin to experience running as suffering or pressure, but as something that can accompany them throughout life. That endurance running becomes a very natural form of physical and mental care.

And if we are honest — for the long-term, lifelong health of most children today, it is probably far more dangerous if they never truly learn to love movement and never learn to calmly accept longer periods of physical effort.

Urban Praprotnik

Viri:

1. Graziano, F. idr. Causes of sudden cardiac arrest and death and the diagnostic yield of preparticipation screening in young athletes: a 20-year experience. British Journal of Sports Medicine, 2024.

2. Smallcombe, J.W. idr. Thermoregulation and dehydration in children and youth during exercise in the heat. British Journal of Sports Medicine, 2025.

3. Hew-Butler, T. idr. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference. Clinical Journal of Sport Medicine, 2015.

4. DiFiori, J.P. idr. Overuse Injuries and Burnout in Youth Sports: A Position Statement from the American Medical Society for Sports Medicine. British Journal of Sports Medicine, 2014.