Triathlete In A Wetsuit Getting Ready To Swim Right Before A Triathlon

Choosing the Right Cold Water Wetsuit for Triathletes

BY Carrie McCusker

Open water swimming can continue even as temperatures drop. Learn the key factors to consider when instructing your athletes in picking the right wetsuit.

Temperatures are dropping in the northern hemisphere, but that doesn’t mean the end of open-water swimming. As cold water surfers have long known, the right wetsuit makes all the difference. Performance wetsuits offer a blend of factors that help hold body heat while continuing to allow an adequate range of motion and comfort. 

Unlike surfers, swimmers spend more time fully immersed in water and benefit from increased mobility and flexibility in the shoulder and arm of the suit. 

The construction of the suit enhances buoyancy in the torso and legs, allowing for improved body position in the water. Also, suits designed for triathlon competitions should be relatively easy to remove.

Wetsuit manufacturers manipulate these variables in their products resulting in unique combinations. Specifically, based on the choice of materials, most suits offer a recommended water temperature range. 

Each suit is constructed for success in a particular activity — for example, multisport (triathlon, swimrun) or open water swim competition versus surfing or paddling. Major contributors that differentiate wetsuits include fit, type of neoprene, zipper style, lining materials and the presence of taped seams that increase both comfort and durability. Finally, budget matters as wetsuits designed to meet expectations in each category come with a big price tag.

The Balance Between Insulation and Flexibility

Most wetsuits are made of neoprene, which acts as an insulator. While a wetsuit may allow a small amount of water to enter, the water is rapidly heated by the body and acts as an additional form of insulation. 

Neoprene comes in a number of different forms, derived from petroleum or from a process using limestone. Petroleum products should be avoided. 

A newer material, Yulex, is derived from plant sources and has superior environmental qualities. 

Yulex has limited use in suits designed specifically for endurance sports, although one company, Ruby Fresh in New Zealand, is marketing a Yulex suit designed for freshwater competition.

Most swim and multisport wetsuit companies use a combination of Yamamoto neoprene. This is a closed-cell structure made from limestone. The company notes the material is lightweight and flexible with high heat retention. Thanks to the very dense, closed-cell interior structure that traps nitrogen gas within each cell, the material is excellent for suits that are made for high activity. 

A unique element in the structure is the maintenance of flexibility or stretch, meaning more form-fitting comfort. Most wetsuits use a combination of Yamamoto #39 and #40, with #40 differing only in its superior flexibility — which is often beneficial for the shoulders. 

The addition of specific thermal wetsuits to the performance line generally denotes a layer on the inside of the suit that adds warmth. For example, Blue Seventy’s Thermal Reaction wetsuit boasts a highly insulated, mid-weight zirconium jersey lining, while Zone 3’s Thermal Aspire has a heat tech fleece lining with a 100% Yamamoto exterior.

Even without thermal linings, looking at temperature ratings for individual suits and examining the use and type of neoprene means the possibility of balancing the properties of stretch with warmth to select the right suit.

Measurements: Finding the Right Fit

Most surf suits and higher-end endurance wetsuits are described by thickness. A thicker neoprene/rubber generally means more float with the loss of flexibility. 

Measurements are described in millimeters of thickness and are written in the form of two or three numbers. For example, a wetsuit that is described as 3/2 mm thick has 3 mm of neoprene in the core and 2 mm in the arms and legs. 

If there are three numbers, for example, 5/4/3, the suit has 5 mm of thickness in the core, 4 mm in legs and 3 mm in the arms. 

Obviously, the warmest and most buoyant material should be in the core. Some suits add thicker neoprene to increase leg float while minimizing thickness in arms and shoulders to enhance freedom of movement.

It is universally important in all wetsuits that they fit properly, but perhaps this has more impact when cold water swimming. 

Note that the suit form fits, doesn’t pinch, and in particular, is comfortable around the neck. A very tight suit might ease up and feel better once in the water, so pay attention to manufacturer recommendations and, in all cases, look to try a suit on before committing.

It’s essential that water is not able to flush through the suit. 

Suits designed for cold water need to keep water from flushing in and out. A little water on the inside is fine, but if the suit doesn’t fit well or has inadequate seams, it’s not going to keep a swimmer warm.

In particular, the zipper and neck should be constructed to keep water out while continuing to reduce friction. Some suits have taped seams to prevent water from getting in, although many suits employ critical taping only when the tape is applied to seam corners, connection points or particular areas of the suit.

How Much Do Cold Water Wetsuits Cost?

Cost can range from around $300 to over $1000, but remember that beyond the price tag, it’s essential to look at the properties of the suit. A swimmer may be willing to sacrifice some of the flexibility of more expensive neoprene to gain thickness for open-water training. 

If an athlete isn’t racing in the suit but wants to use it for offseason training only, getting all the expensive properties that assist in speed and fast removal can be traded for warmth. 

Remember that fit and comfort matter. Swimming around in a bulky wetsuit that doesn’t allow a good range of motion in arms or shoulders or chafes the neck with head rotation isn’t worth the investment.

Several companies offer thermal vests or layers that can be worn under a wetsuit to increase core warmth and are a good lower-cost place to start. Add to that an insulted cap, socks and gloves, and an athlete may be able to get by depending on their particular climate conditions.

It goes without saying that cold water swimming has inherent risks. In advising athletes on wetsuit purchases to increase time in the open water, it is incumbent upon the coach to ensure the athlete recognizes the signs of hypothermia, avoids swimming alone and engages in prompt recovery protocol after swimming. 

This includes having a warm car or building nearby and dry, warm clothes. Never swim alone or without having someone nearby. Hypothermia can sneak up quickly as water and air temperatures drop.

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About Carrie McCusker

Carrie McCusker is a level 2 TrainingPeaks coach and a lifelong athlete who enjoys bringing individual attention to every level of athlete. You can find her on Strava and Instagram or check out her coach profile at TrainingPeaks.

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