Why 31°C Is Too Warm For Open Water Competitions

Why 31°C Is Too Warm For Open Water Competitions

With water and air temperatures soaring in some parts of the northern hemisphere, the issue of what water temperatures are too high is being discussed by some race directors again.

It remains a difficult topic to come to a consensus.

Some national swimming federations have instituted a maximum water temperature of 31°C (87.8°F).

Other have instituted rules that considered a combination of both air and water temperatures (where air and water temperatures added together in Celsius cannot be above 63°C or 177.4° F for an open water swimming race to be held).

Other national swimming federations follow FINA guidelines where there are no specific maximum water temperature rules, only recommendations that counter-measures be considered if the water temperature exceeds 31°C (87.8°F).

The practical issue in adhering to the FINA guidelines is three-fold: 1. The 31°C maximum is not necessarily dangerous for the lean teenager with a low body fat percentage who trains at high intensities 5-8 times per week. However, the 31°C guidelines are much more significant for the under-trained and overweight adult swimmers who are increasingly participating in an occasional open water swim. When national and international governing bodies sets the bar (or recommendations) at 31°C, this standard influences many of the sanctioned and non-sanctioned 6,500+ open water swims around the world. In these swims, there are many more overweight adult swimmers doing the races than the number of lean teenagers in the high-level competitions. Those with a higher body mass index (BMI) are less able to dissipate heat from their core, making cardiac arrhythmia and other heat related events more likely. Adults are also much more likely to have concomitant health issues and medications that may affect their hydration and temperature regulating systems. Although the risk is higher for these older, under-trained individuals with higher BMI indices, race directors point out that “31°C is OK with FINA.”

2. Water temperatures are usually measured the day before or in the cooler morning hours before the open water swims start. Although a race director may be satisfied that the water temperature falls under the 31°C threshold, when the sun rises the land and water temperatures also gradually increase. Rare is the race director who re-measures the water temperature during an event, even though it is clear that air and water temperatures have increased. But race directors can point out that “the water temperature was measured below 31°C before the start of the race.”

3. Race directors are, almost without exceptions, locals. That is, they live and work in the area where the open water races are held. Their own bodies are acclimated to the local temperatures. But with the increasing popularity and mobility of the open water swimmers, swimmers in warm-water venues often come from parts of the world that are climatically cooler. These visitors are not accustomed to tropical heat or extreme dry heat, especially when they are taxing their bodies in stressful ways in the heat of a competition.

All things to consider for the safety of all.

Copyright © 2012 by World Open Water Swimming Association