Why 31 Degrees Celsius in Open Water Swimming? Part 3 — Why Open Water Swimmers Are At a Disadvantage

By Steven Munatones, Swimming World Open Water Contributor

Editor's Note: This is the third in a three-part series on FINA's rules that allow open water swims to be conducted in water over 31 degrees Celsius (87.8 degrees Fahrenheit).

Click here to read Part One.

Click here to read Part Two.

HUNTINGTON BEACH, California, October 29. WITH FINA's decision to allow competitions in water over 31 degrees Celsius (87.8 degrees Fahrenheit), we looked at land-based endurance sports for some guidance.

Land vs. Water Endurance Athletes

Swimming in 31 degrees C under a scorching sun has risk written all over it.

Swimmers racing under such conditions put themselves in at least an equally dangerous situation as triathletes, marathon runners and cyclists who are competing under warm temperatures on land. And probably even more so.

Observers point out that Hawaiian Ironman athletes compete for significantly larger cash prizes as they run and cycle in the hot lava fields on the Big Island of Hawaii. In the tropical heat and humid, these races are, undoubtedly, brutal. Running through a lava field is like running in an outside oven. Cycling in the desert into the famous Santa Ana winds of Southern California is like peddling into a blasting furnace.

But there are very important and fundamental differences between marathon swimmers who compete in FINA-sanctioned races and those endurance athletes who compete in triathlons, running marathons and cycling races under extreme conditions around the world. The situation and behaviors of these land-based endurance athletes differ in fundamental ways from marathon swimmers:

1. Land-based athletes can cool themselves
They pour cold water on their head; they wear ice packs; they stop under the shade; they sit down or stretch. Even if a warm wind is blowing, when they pour water on themselves, the skin is cooled somewhat through evaporation. Marathon swimmers do not have this opportunity. They compete in an environment that is constantly warm. They do not pour cool water on themselves; they do not put ice packs under their swim caps or in their swimsuits. They do not stop. There is no practical way to cool themselves other than to stop and quit the race.

2. Land-based athletes shade themselves with sun visors or hats
In contrast, marathon swimmers wear rubber or silicon caps on their heads. While some men remove their caps (note: swim caps are mandatory for athletes at the start of FINA races), many athletes keep their swim caps on their head for the entire race. Swimmers do not wear white; in fact, the elite athletes do not even use white-colored zinc oxide on their backs or legs during a race. Imagine a runner, triathlete or cyclist who competed with a tight-fitting rubber cap on their head during a triathlon or marathon run. That scenario simply does not work.

3. Land-based athletes adequately hydrate
Watch a marathon run or triathlon in warm conditions. The runners and triathletes hydrate over the entire race, taking in liquids over 50 — 100 meters while constantly sucking on their water bottles. In contrast, the marathon swimmers take quick sips in less than five seconds as they pass through a single feeding station (in a loop course) or every 15-30 minutes if they have an escort boat. Of course, it is the decision of the athlete and their coach how often they hydrate, but hydration is a much more complex action in the water during a marathon swim than it is during a marathon run or triathlon on land.

4. Land-based athletes can wear reflective clothing
Runners often wear white or light-colored, loose-fitting jerseys that protect the skin when the sun is beating down on them. In contrast, marathon swimmers wear tight-fitting dark swimsuits as they swim horizontally in the water, fully exposing their backs and legs to solar radiation. While the land-based athletes dress to minimize the effects of heat, the marathon swimmers do the exact opposite (i.e., wear black or dark blue, tight-fitting swimsuits that trap body heat).

5. Land-based athletes train for extreme conditions
Runners and triathletes who know they will compete in an ultra-marathon in the desert or the Ironman in Hawaii adequately prepare themselves for these extreme conditions. They acclimate over a period of time as they concentrate on preparing themselves physiologically. In contrast, the elite marathon swimmers usually (and almost exclusively) train in a pool where the water temperature is constantly comfortable. If they do train in the open water, they train in open bodies of water that do not have the extreme warm conditions. That is, marathon swimmers most likely do not acclimate well (or well enough) for extremely warm-water conditions. Their bodies are not adequately prepared for 31 degrees C. While it is ultimately the responsibility of the athletes to prepare for such conditions, they are also competing in cold-water conditions throughout the year. The human body needs much more time to adapt to extreme conditions.

6. Land-based athletes are closer to emergency care
The warning signs of heat stroke (red, hot, and dry skin without sweating), rapid/strong pulse, throbbing headache, dizziness, nausea, confusion) is much easier to see on land than in the water. Volunteers, officials and safety personnel know instinctively when a land-based athlete is having problems. It is more difficult to assess the situation in the water, especially for the untrained eye. So not only are the athletes in the water apt to receive care in later stages of heat stress than land-based athletes, but they are also in an environment where they must first be pulled from the water, taken to shore, and then driven to emergency help.

7. Swimmers have less experience with heat exhaustion and heat stroke
Athletes – even swimmers – know when their bodies are overheating on land. They sweat profusely, their skin is flushed, their heart rate increases. They know instinctively to slow down or stop, get some water and get out of the sun. This happens as a child playing around in summer and it happens as an adult overdoing it on a hot day. But most swimmers have little or no experience with these feelings during competition. They will not know instinctively what is happening, especially in a competitive situation. With their head down, alone with their thoughts, they are trained to keep on going. The danger is that unconsciousness can happen so quickly – and in the water, this is potentially deadly.

Experienced individuals know that there is a difference of “environmental dissipation capacity” between swimmers and land-based athletes. Ultra-marathon runner, triathlete and marathon swimmer Bruckner Chase explains, “Athletes on both land and water occasionally compete in an environment that is constantly warm. The difference lies in the application of the environmental dissipation capacity, and the athlete's ability to dissipate heat through a number of means from conduction to evaporative cooling to preventing radiant heat gain.”

Real-life Situations

At the 2005 and 2011 FINA World Swimming Championships, this writer cradled the head of a distressed athlete in his arms in a 25km race. He saw the pleading eyes of an athlete reaching out for help. No words, no body language, just human-to-human eye contact.

These athletes were not looking for help to win a race. They were not asking for help to get a medal. They were asking for help … to live another day. To cradle the head of a distressed athlete in one's arms enables one to profoundly understand how important safety is.


In summary, does FINA's new rule regarding maximum water temperature aid in the safety of its sanctioned races?

If FINA believes these new rules are conducive to ensuring safe competitions, then it would be greatly welcomed if FINA's experts publicly explain why the situation is sufficiently safe. Any explanation — via a written document or through a controlled interactive webcast — would go far in helping the open water swimming community to understand its reasoning.

If there is indeed no problem, then FINA would do a great service in educating the world's swimmers, coaches and administrators. As the global open water swimming community grows, it is looking to FINA for leadership.

Steven Munatones is a former national marathon swimming champion and coach, and can often be found on a pontoon or chase boat in many of the biggest open water swims. He is the editor and founder of The Daily News of Open Water Swimming.