Why do triathletes wear a wetsuit?

In this CQFD section (“Ce Qu’il Fallait Démontrer” – What Had to Be Demonstrated), we answer your questions and address your preconceptions about cycling and triathlon. Simple questions, but not necessarily obvious answers for novices or those unfamiliar with our sport.

Are you registered for your first triathlon and wondering about the benefit of a wetsuit for the swim? For all formats and athletes of all levels, know that wearing a “neoprene” suit is justified for more than one reason. Explanations.

By Pierre-Maxime BRANCHE. Photos: Orca and Christophe Guiard

If you’re new to the triple discipline, many equipment questions arise for each sport. And if you’ve already attended an event to support family or friends, you’ve surely noticed that army of penguins at the swim start in that uncomfortable, super-tight full-body suit that molds every square centimeter of the body and every little bulge. Some seem very uncomfortable once they’ve forced their way into it, others parade around as if it were a second skin. But most of the time, apart from a few die-hards, aliens, or eccentrics, all athletes at the start put it on, and if you talk to them, none would consider starting without it.

Sometimes mandatory, sometimes forbidden

Indeed, for various reasons, wearing a wetsuit is almost mandatory for triathletes of all levels. Triathlon swimming is specific because it takes place in a natural environment: canal, body of water, lake, sea, ocean… This setting is important because the water temperature dictates whether or not a neoprene wetsuit must be worn. The 2019 regulations of the French Triathlon Federation state that for water temperatures below 16°C, the wetsuit is mandatory. Above 21.9°C (XS to M distances) and 24.5°C (L to XXL distances), it is forbidden. In conclusion, for water temperatures between 16°C and 21.9°C or 24.5°C (depending on your event format), the choice is yours. But then, if you have the choice, why wear a neoprene wetsuit?

Thermal protection above all else

While it has become a true performance tool today, the neoprene wetsuit was originally designed as protection against the cold. Even when swimming at a good intensity, the body cools down quickly in the water. This is its primary function: to allow your body to operate in adequate thermal comfort, regardless of the swimming distance to be covered, especially over long distances. On the one hand, the thickness of the material (neoprene + jersey) insulates you from the cold water; on the other hand, despite an extreme fit (if it’s the right size), your wetsuit will allow a slight trickle of water to pass between the material and your body. In contact with your skin, the water will warm up, helping to insulate your body to maintain thermal balance and thus delay a possible hypothermia situation. This temperature maintenance has another benefit: it limits energy expenditure (see elsewhere) since the body is aided in its struggle for a good internal temperature.

Improve your buoyancy

Except for mermen, water is not the natural environment of homo sapiens. Depending on our experience, our abilities, our training, and our genetics, we don’t all swim in the same way, especially in terms of body position in the water and buoyancy. Due to body density, some float while others sink! Buoyancy is, however, one of the most important criteria for more efficient movement and thus better performance on the stopwatch. This primarily affects the entire lower part of the body, from the lower abdomen to the calves: the thicker a wetsuit is, the more it will allow you to keep your legs towards the surface, and the better your swimming position will be.

The neoprene wetsuit allows, to a certain extent, to correct your flaws and be more efficient

Incidentally, this reduced effort to maintain a horizontal position in the water will also save energy for the swim, but also in anticipation of the bike and run. Finally, to be effective, the crawl stroke requires very good technique, which degrades over minutes. A poor movement corresponds to extra effort to move forward, thus greater energy expenditure, and thus an earlier onset of fatigue. The neoprene wetsuit allows, to a certain extent, to correct your flaws, to be more efficient than with just swim briefs, and thus to delay the onset of fatigue. Moreover, it’s no coincidence that among professionals, good swimmers prefer when wetsuits are forbidden because it allows for real gaps to be created by revealing skill levels, whereas wearing a wetsuit levels them out.

Optimize your hydrodynamics

On the eve of the race, you can hunt down every last stubborn hair on your entire body (which, between us, is already an achievement!), but your skin will never be as hydrodynamic as the neoprene coating of a wetsuit. Especially if you’ve invested in a very high-quality neoprene in terms of flexibility, lightness, and featuring a Super Composite Skin coating renowned for its hydrophobic and anti-friction qualities. Much smoother than your skin, a wetsuit therefore significantly improves your glide by reducing friction in the water and your hydrodynamic drag, for an undeniable gain in speed. Over long distances, this gain can amount to several minutes, which is not negligible for both the first and the last… A real shark skin! Or baby shark, depending on your preference.

Limit energy expenditure

As we’ve seen, wearing a wetsuit helps limit energy expenditure on several levels: firstly, by helping your body maintain its thermal balance; secondly, by improving your buoyancy and thus correcting your flaws to be more efficient and delay fatigue; finally, by optimizing your hydrodynamics to gain speed. All this, for less effort! Added together, these marginal gains are not to be overlooked: all the energy preserved will allow you to approach the other two disciplines with more clarity and better manage your effort. Bike then run, the road is still long.

Build confidence

This is both a reason that justifies wearing the wetsuit, but it is also and above all a consequence. In a bike park, when the announcer announces the water temperature an hour before the start, faces tense up. When wearing the wetsuit is officially authorized, those same faces relax. Except for good swimmers, the wetsuit is an assurance, a guarantee, a pledge of confidence. For triathletes, the swim leg is most often the most dreaded discipline. Being in a “wetsuit” means spending less time in the water, covering the distance more easily to move on to something else more quickly. It means protecting and reassuring oneself in the event of a mass start, which is often destabilizing or even oppressive. It means being sure to float, even if the stroke is not mastered or fatigue sets in quickly. It means losing less energy if the start takes place in the water and you can’t touch the bottom. It’s a source of warmth if the water is cold and you’re sensitive to cold. It’s also the feeling of belonging to a community, of being part of the same adventure, with its personal challenges and its own fears. Finally, it can be a tool for concentration. Because once it’s on and the zipper is closed, you know that the seconds are ticking.

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