Risks and dangers for racers in Swimrun

As a prelude to the discussion about the risks of Swimrun on the body, it seems essential to present this activity in full expansion in Europe and throughout the world.

There were 40 races in Europe (2-3 countries maximum) but today there are more than 50 events in France alone. France being the second nation after Sweden the cradle of the discipline in terms of race and competitor.

But this is important, the Swimrun is also in his mind outside the races in training sessions or simply sharing a sporting moment with other people. For a while, communities are forming and outings are organized without any goal to go towards the competition but only enjoy the moment. Some even engage in adventure roaming Swimrun by transporting bivouac equipment like The Swimrun Mediterranean raid last June or the expedition to Lake Baikal scheduled in the summer of 2018.

However, it seems to me essential to follow the initial approach of the 4 Originals and commit to the following 4 pillars.

These 4 pillars enrich this sport and give it his universality.

  • Effort: A symbol of sport with or without competition and where everybody can to excel yourself or in group
  • Sharing: Sharing with a partner making the Moment even more intense but also a guarantee of safety in open water or in trail as soon as one is in isolated areas. The union of our forces helps us to move forward.
  • Respect of Human: Respect for competitors and just a friendly moment . In addition, we want a clean Swimrun without doping
  • Respect of Nature: That is essential everybody limits his impact on the fragile environment and learns about the different possibilities of path. Let us to live in the respect and universality of this population.


Now that we understand a little more about the Swimrun, we will clarify the dangers and risks of this sport.

Most incidents during swimrun releases are injuries following a fall or shock. The terrain and the environment maximize the risk of falls on slippery rocks or the technical level in trail running. However, there are many other phenomena to consider.



security and tactics

Biological function of the body ensuring the constancy of the internal temperature of the body (homeothermia) and balancing thermogenesis and thermolysis.

The exercise seems easy but finding this balance (homeothermic) between swimming in cold water and race with combination defines the main difficulty of this sport.

If thermogenesis prevails, we risk hyperthermia and if the thermolysis is superior, the risk is hypothermia. All this is simple but the dangers are real and very quickly present.


Hypothermia is mostly in direct connection with the middle of swimming in cold water.

The use of neoprene suits is essential below 20 ° C.

In Swimrun, we encounter only moderate hypothermia and that vs the duration of the race.

The signs and occurrence of hypothermia in swimrun are increased by:

  • dehydration (ergonomics of the race, number of energy stations, accessible drinking water, salt water ..)
  • tiredness induced by poor diet (calorific balance), also the climatic conditions (wind, humidity according to the geographical areas)
  • thrills

During the first swimming in open water in cold water, the main risk is not the hydrocution but the drowning with ++ adrenaline (inhalation with acute pulmonary oedema and heart arrets possible)


Hyperthermia appears very quickly in Swimrun and the consequences can be lethal :

  • dehydration
  • tactical choice to stop in energy station
  • some doping products increase the thermogenesis
  • The wetsuit is the masterpiece of hyperthermia. In swimrun, they provided with a rear zip but also before to ventilate the body during the effort.
  • It is essential to remove the swimming cap during the race sections

The direct consequences of a malignant hyperthermia are:

  • fast tiredness
  • nausea and diarrhea
  • cramps by the electrolytic losses (sweat ++ according to hygrometry for example)
  • an intense thirst with a “roasted” tongue (dysphagia by collapse of salivary secretions)
  • a psychomotor behavior with an aggressive tendency with an increase in spatio-temporal disorientation
  • heart arrest with global rhabdomyolysis

As we saw earlier, water is an important unknown in Swimrun

It emerges from the tactical choices during a race or training to limit the water losses of our body but to bring the sufficient volumes.

The tactical choices will be:

  • location of the course with water points
  • drinking water in the lake ideal to hydrate during the swimming sections (Lake Annecy, ….)
  • flask in wetsuit, belt
  • salt water, the risk of diarrhea and abdominal pain is increased be careful with microbia-abdominal pathologies as well as ORL


The Swimrun is an exciting activity that requires to know his physical and mental capacities (without overestimating oneself) but also to share with others for pleasure and security.

Conditions are updated, sessions are planned (choice of gear, food, water…….)

“Considering that the numbers of swimrun races are growing and since they are now held in many different kinds of freshwater / brackish / saltwater environments, close to cities, near farmland or in this information is even more relevant. Further down we have listed some dangers from microbes, algae and jellyfish found in temperate climates and what you can do to avoid them. In short, to protect yourself »

/ JC Bastiani swimrun coach & nurse

The Day After ÖtillÖ – How the body recovers

WoW, what a race.

Tough conditions and challenging elements, just like it should be. ÖtillÖ really presented itself from its best side, the raw beautiful nature!

And still we saw sub-8 hour times!

But how does +75 km of fighting in these harsh conditions affect the body, and what should you think about when trying to recover?

Apart from pizza and beer, there are some quick tips to have in mind, especially if you are a bit older.

Have a read below and remember that there are no short-cuts in the recovery process, which is highly individual.

Association of Academic Physiatrists (AAP). “How the body recovers from an ultramarathon.” Science daily, 18         February 2016. 

Ultramarathon runners can expect an approximate five-to-seven-day subjective recovery post race, according to research presented this week at the Association of Academic Physiatrists Annual Meeting in Sacramento, Calif. The study also looked at factors that affect physical recovery and a runner’s ability to return to full running speed after participation in an ultramarathon.


(Full study can be found here http://www.tandfonline.com/doi/full/10.1080/02640414.2016.1183808 )

/The WoS Team

Swimrun Health Dangers on Land and Water

It’s time!

The season and the training kicks in. Take care out there and don’t forget about all the dangers!

/The Wos Team

*Originally posted in 2016*

Swimrun is a sport that has great health benefits, there can be no doubt about it. Swimming and running outdoors ensures you get a full body workout whilst filling up your reserves of vitamin D from the sun. Changing between swimming and running is great for not overstraining muscles and running and swimming on uneven terrain and in open water engages far more important core muscles than in a static controlled environment. So you might wonder why we should take some of the fun out of it by bringing up rare dangers that are unlikely to affect you. Well, simply because by being aware of these dangers and the necessary precautionary measures might help you avoid the risks altogether and let you head out knowing you will be at minimal risk of serious consequences. Continue reading “Swimrun Health Dangers on Land and Water”

Training and sex, or is it the other way around?

Credit: Digital romance 

Train as little as possible, or at least very short sessions to have more sex!

Pre-season is almost over and training focus will now shift from building strength and stamina towards improving overall speed, trying to hit the performance peak just before the next race.

Training with the aim to win, or to position oneself in the top-tier, comes with many benefits and some disadvantages. For many, this type of training focus helps structure general life, have positive impact on overall health, well-being and specifically on lower body weight, aerobic and anaerobic fitness, cardiovascular health and so on. This well-being is also interconnected to cognitive and mental health.

Continue reading “Training and sex, or is it the other way around?”

How to swim during a swimrun race – Be smarter, faster and save energy – Use a pull-cord!

In the early days of swimrun, very few used a pull-cord of any sort, whereas today this equipment has become standard in team swimrun racing. Its main purpose is to help pull the weaker swimmer during the swims but despite this great benefit, some teams still opt for racing without one. This is totally fine, but the options should be weighed carefully, because you might gain several benefits from using a pull-cord.

A standard pull-cord
A standard pull-cord

Continue reading “How to swim during a swimrun race – Be smarter, faster and save energy – Use a pull-cord!”