As with most sports, some will always look for ways to push things to the absolute limits of human capability.

From Captain Matthew Webb first swimming the English Channel without aid in 1875, to the recent awe-inspiring effort of 37-year old Sarah Thomas, an American cancer survivor who swam the Channel FOUR times in a row without stopping, some events show just what we’re capable of.

In the spirit of these superhuman efforts, the sport of marathon swimming is a unique world within the swimming discipline.

This article is an introduction to the sport of marathon swimming, which makes the sport and its competitors unique, and some of the unorthodox training considerations that go into preparing for marathon swim events.

What is Marathon Swimming?

A marathon swim is:

An endurance swimming race of 10km, recently included in the Summer Olympic Games in 2008. These races take place in open water, such as rowing basins, recreational lakes, or the ocean.

Longer marathon swim distance events exist, such as the 25km race at the open-water World Championships. This would be something like the swimming equivalent of an ultramarathon, so we’ll stick with the 10km distance for now.

An official marathon swim includes 25 competitors. The course can be A to B or laps, for example, Olympic marathon swimming involving four 2.5km lengths with four buoy turns, with feeding stations along the way.

Part of the reason behind the naming of a marathon swim is the similar average finishing times to a running marathon - around 2 hours at the elite level.

The distance, setting, and rules of marathon swimming make it a very unique sport. So what sets athletes who enter swimming marathons apart?

Unique Characteristics of Marathon Swimmers

Elite level open-water ultra-distance swimmers generally have different physical and metabolic characteristics compared to pool swimmers. Some studies show a difference in swimmers height and weight, with elite open-water ultra swimmers to be smaller and lighter than pool swimmers.

On the other hand, a higher body fat composition can be of benefit in the open water as insulation against cold water temperatures.

There is also a unique relationship between men and women athletes’ performance in marathon swims. One study found that the fastest women were 12-14% faster than the fastest men in an ultra-distance swim with water temperatures under 20 degrees celsius.

The same study revealed that over the years, the average age of the fastest marathon swimmers has increased.

Some notable marathon swimmers include Ferry Weertman, the Dutch Olympic gold medalist in the 10km marathon swim in the Rio 2016 Olympics; his female counterpart, Sharon van Rouwendaal, also Dutch and the female gold medalist in the same event at the same Olympic games.

Other big names in the sport include Keri-Anne Payne, the two-time 10km open water world champion from England, and Petar Stoychev, the Bulgarian legend of marathon swimming, who won 11 consecutive titles at a major international open water marathon swimming series since 2001 and has over 60 wins in individual swimming marathons.

With these amazing athletes as inspiration, let’s look at how one prepares for a marathon swimming event.

Training Considerations for Marathon Swimming

Marathon swimming training not only needs to include the heavy volume and distances required of the sport, it must prepare the athlete for the many unpredictable factors in such a long open-water race.

This means that while pool training is fine for technique and conditioning, it must be mixed with open-water training to allow one to become accustomed to the ever-changing environment that can change a race at any time.

Racing in open water

Any triathlete will be aware of some of the elements that make open-water racing a different beast. From the waves, swells and tides of whatever location the event is held, to the weather and water temperature - a few degrees can make all the difference in this sport, especially as special equipment to retain heat is not included in the standard equipment allowed.

Navigational IQ is another critical skill of a marathon swimmer - when elbows and feet are hitting you from all sides as swimmers jostle for position, you need to maintain a keen awareness of your surroundings and your direction to ensure no effort goes wasted.

These are some of the factors that make marathon swimming a sport with a significant psychological component - a trait it shares with other endurance and ultra-endurance disciplines.

Mind the muscle cramps

In terms of intensity of training, marathon swimming has been researched to be performed most successfully at below anaerobic thresholds. This requires the ability to maintain a swimming velocity that avoids allowing your blood lactate to peak, especially when you may have hours left in the water.

Many less experienced marathon swimmers have trouble consuming enough energy and carbohydrates in the water. This can greatly affect performance, not to mention become a risk to health.

Train both in the water and on land

Athletes have been shown to lose close to 2kg during a race. To maintain proper nutrition and train to consume whatever combination of solids and fluids that most comfortably allows you to perform at the required level.

In a sport like marathon swimming, the risk of repetitive injuries that higher level swimmers deal with gets exponentially higher. That means that a critical component of a training program should include dryland exercises for strength and injury prevention.

As for how to fight off jellyfish and sharks… perhaps a topic for another article.

We hope this article has been a good introduction to some of the things that make marathon swimming such a unique and exciting sport.

Let us know if marathon swimming is something you’re considering getting into in the comments below!