Running counts among today’s most popular sports. Sometimes the race is on even before the competition itself has started, as tickets for events sell out within hours. In France, this has got people talking about a “race for the runner’s bib”.

So, while running enjoys the reputation of a wholesome sport, the reality is that some of us feel stress at the simple prospect of donning a bib, while even a greater number of us face exhaustion upon completing a race such as a marathon or trail. So, what exactly is the toll of the sport on our bodies, and does our status as an amateur or a pro make a difference?

Working it out like a pro

It’d be easy to place professional and amateur runners in two separate boxes. Indeed, pros train hard–up to three times a day ahead of certain races. Life at those times is austere, punctuated by meals, runs and sleep, leaving little room for improvisation. And while you might think that the countless events around the world might dilute some of the demand for them, competition in such a universal sport is in fact fierce and professional runners need to push their bodies to the limit to get better at it.

High-level careers are often brief, lasting five or six years. Stories such as that of Eliud Kipchoge, the first man to run a marathon in under two hours (under non-certifiable conditions), sixteen years after becoming world champion in the 5,000 metres on the track, remain exceptions.

The significant mechanical stress inherent in the sport weighs on the muscles, tendons and skeleton. There are times when rest periods are short and it’s increasingly common to see athletes injuring themselves during competitions on live television, a surefire sign of physical and mental exhaustion. Some might consider these factors to be fairly typical: after all, these are top-level athletes.

Similarities between professionals and amateurs

But are world champs, next-door champs and ordinary runners really that different? Considering the tip of the iceberg of this question, the answer seems obvious: they don’t run at the same speed and therefore don’t spend the same time exerting themselves. But what about the submerged part: the pre-race prep, training, the individuals’ investment and self-sacrifice? When you want to break a record–your own record–don’t you give 100% of yourself, both physically and mentally?

Let’s consider the figures for the Paris Marathon in 2025: 56,950 registered for the race, 55,499 finishers. The mass event spells the same challenge for all: 42,195 km (around 26 mi) for the fifty or so athletes who might be considered elite and all the others who have to juggle it with their professional and family lives.

In truth, regardless of your level or speed, there are many similarities in how you prepare for a marathon, with identical training loads. Marathon training typically lasts ten to twelve weeks and includes essential elements such as “long runs”, a training session of around thirty kilometres recommended once a week.

No one escapes it. And there’s a whole range of science-based books on running, designed to guide the general public.

However, as training takes its toll on both body and morale, the risk of injury rises.

Trail or marathon prepping: increased risk of injury for amateurs

In fact, we most often see stress-related injuries among amateurs.

A high-level athlete doesn’t need to see a sports doctor. Why is that? Because they have built their careers over many years and have specific genetic characteristics that allow them to take on heavy training loads. They follow a specific programme that includes dietary measures, recovery phases and processes.

Professional athletes benefit from much better general and medical support than novice or amateur runners who, whether for individual or collective challenges, embark on projects such as marathons or trail running. This is how a runner like Christelle Daunay, after fifteen years of practice and modest beginnings at the national level, patiently built herself up to win the European Marathon Championships in Zurich in 2014.

When physical stress takes its toll on professionals

The issue of physical stress has been raised for a long time. In the 1990s, it was already reported that simply running for 45 minutes rather than 30 minutes a day could double the frequency of injuries. Going from three to five weekly sessions had similar effects.

Christelle Daunay was no exception. She suffered a stress-related fracture in 2018, which prevented her from defending her title as European marathon champion in 2014. It should be noted that a “stress fracture” is a bone injury, similar to a crack, which can be caused by running long distances.

When ultra-trail puts body and mind to the test

The recent development of trail running (i.e. running in the great outdoors) only reinforces these concerns, with not just the wilderness but “ultra” aspect appealing to many.

The extreme sport has its own particularities. Due to the irregular terrain, its practice requires different joint and muscle movements and therefore greater concentration than road running. Add to that the effort’s duration, ranging from a few hours to a full day or more, the issues of nutrition, effort management, and muscle damage that sets in over time, and it’s easy to understand why these events lead to mental and physical fatigue, not only during the event itself, but also in the long term.

The conditions of running-related physical wear depend on many factors and vary from person to person. For example, on whether you jog to hit a speed or mileage goal.

Wearing out the body at a given moment to increase its resistance… to wear and tear

Whatever the focus, people often engage in specific training programmes, with physical and physiological progress relying on the human body’s remarkable adaptive capacity.

Note the paradox here: one of the principles of training is to stimulate the body, to “wear it out” at a given moment in time in order to trigger the physiological processes that will lead to improved capabilities, the fight against fatigue… and, ultimately, increased resistance to physical stress.

This fundamental process is the basis of physical rehabilitation/recovery programmes, which are increasingly used in physiopathological contexts, for example to treat peripheral artery disease or obesity.

However, at its most intense, training can require mental commitment, resistance to weariness, and a strong will to continue the effort over time despite fatigue.

Stress can therefore also be mental. This is perhaps the major difference between amateurs and professionals, who have no choice but to put their bodies under severe strain in order to progress in the high-level hierarchy.

Pros or amateurs, the importance of good coaching

Seeking to push their physical and mental limits can lead any runner to feel “worn out”. All these factors highlight the importance of being well supervised and advised (by coaches, in clubs, etc.) in order to train with a certain progression, both in terms of quantity and intensity, and to adapt one’s lifestyle.

No technical equipment is needed to run – an advantage which allows you to ideally experience your own body, provided you’re aware of races’ risks and limitations. And rest assured, if you still don’t enjoy this sport, there are plenty of other options available so you can find something that suits you and enjoy the health benefits of physical activity. What’s important is to keep moving.

Extract from What I Talk About When I Talk About Running by Haruki Murakami:

“Human beings naturally continue doing things they like, and they don’t continue what they don’t like. That’s why I’ve never recommended running to others. It doesn’t suit everybody. Similarly, not everyone can become a novelist.”

Benoît Holzerny, a health-promoting sports coach, and Cédric Thomas, a top athlete trainer (including the 2014 European marathon champion, Christelle Daunay), contributed to writing this article.