This guide is courtesy of our friends at Zone3 US

What’s in a tri suit, really? For a lot of people, the price tag is their only consideration but there’s a lot more you should consider. There really isn’t much point in spending thousands on a pair of expensive race wheels and a super-expensive TT bike, while rolling along in a sopping wet, loose and flapping tri suit. For both comfort and performance, quality of kit should be right up there at the top of your list.
For those just starting out, this doesn’t mean you have to spend a fortune – there’s some great entry-level kit. When choosing your kit though it’s important to understand and weigh up exactly what you’re getting for the extra buck. Good kits can have a positive impact on both newbies and pros. Here are a few things to consider.

One Piece vs. Two Piece

There is a choice between buying a one piece tri suit, or the top and bottoms separately. Ultimately, it depends on personal preference and what your body shape feels the most comfortable in.

Benefits of a one piece

  • More streamlined fit, which is more aerodynamic.
  • Contains fewer seams, so less opportunity to rub or cause discomfort.
  • The top won’t ride up and in general will move around a lot less.
  • Helps to hold the shorts up in the correct place.

Benefits of a two piece

  • More flexibility in sizing – you might wear a different size top to bottom, or might be particularly tall, which makes a one-piece tri suit uncomfortable.
  • You have the option to wear these separately in training.
  • Easier for bathroom breaks during the race. This mostly applies to long distance triathlons, where toilet stops can’t be avoided.

Some tri suits come in a short-sleeved version. Again, it is dependant on what is more comfortable for you, but the main benefit of wearing sleeves is sun protection on your shoulders. However, sleeveless tri suits offer more flexibility in the shoulders, especially during the swim. Some people find that the seams on a sleeveless tri suit can rub though, so some athletes will wear a short-sleeved tri suit for this reason.

Short sleeved tri suits can also give you an aerodynamic advantage on the bike section of the race.
Please note that some events and races have specific guidelines regarding kit, so it is always advised to check the rules of your races to double check that you can wear a short-sleeved tri suit.

Swim–Long Distance vs. Short Distance

Zone3 tri suits have been designed with distance in mind, containing a mix of features depending on which distance they are suited more towards…

Swim–Body Position and Core Support

Your tri suit should be on the side of tighter rather than loose. Apart from the fact that all tri clothing will stretch over time, the best tri suits will be designed with strategically-located compression around the core and hips.

In the swim, this ‘holds you in’ and supports the engagement of your core, which increases hip drive and therefore reduces fatigue over the course of the swim.
This is particularly the case with the ‘speedsuits’ used by many people in non-wetsuit races, such as our Zone3 Swim Skins; Speedsuits are worn over a tri suit and taken off in T1. These suits use very stiff fabrics, which compress the whole swimmer providing maximal drive and minimal surface area.

Swim–Drag and Buoyancy

Contrary to popular belief, the most aero/hydrodynamic fabrics are not those which are super smooth, but those which are slightly rough. A smooth fabric allows air or water to attach to it at a molecular level, which creates a ‘tugging’ at the fabric which causes a turbulent (rough) flow around the surface; increasing drag.
Well designed, textured fabrics actually ‘induce’ a very thin, controlled layer of turbulent flow immediately over the surface, which acts as a super-slick surface for the bulk of the air/water flow to move over smoothly (laminar flow).
Our high-end suits such as the Zone3 Lava use fabrics which feel ‘papery’ to the touch, making the most of this principle. While it’s against the rules in most races for tri suits to contain rubberised or buoyant materials, there are some clever tricks for ‘indirectly’ creating buoyancy with hydrophobic (water-repellent) coatings.
As well as assisting in the production of a boundary layer, these coatings significantly reduce the ability of the fabric to absorb water, resulting in the attachment of air bubbles under the swimmer which assist with buoyancy.
The right tri suit or swim skin can save you about 2-4 seconds per 100m over a cheaper suit, depending on your body shape, stroke mechanics, natural buoyancy, and speed. Free speed!

Bike–Drying After the Swim

After emerging from the water, donning your helmet and heading off on the bike, the last thing you want is a clingy tri suit.

This will restrict your range of motion and increase the amount of effort you need to expend to turn the pedals. If you’re wearing a low quality, poorly fitted suit, it may even still be wet from the swim when you arrive in T2 which will mean you have to carry the extra weight around even further. The hydrophobic properties of good quality suits create a wicking action, which moves moisture away from your skin and allows it to evaporate. This reduces the cling-wrap effect and allows you to move more freely and naturally. Higher beading properties also make fabrics faster drying once out of the water. Our Aquaflo™ fabric used in the Aquaflo+ collection features a Teflon coating to help reduce drag and repel water.


Aerodynamics on the bike isn’t just about aerobars and expensive wheels. These days, more and more speed is being found from improvements in the aerodynamics of tri clothing. In addition to the boundary layer principle described above, minimising seams and loose fabric make a measurable difference. As mentioned above, short sleeved tri suits can be slightly more aerodynamic on a bike than sleeveless suits.
Flapping race numbers are another drag contributor, so make sure everything is well pinned down. At 40km/h, over 80% of the power you put out is spent overcoming drag. Saving even a handful of Watts can save you many minutes.

Bike–Comfort in the Saddle

The pad/chamois in a tri suit is a challenging part to get right. It can’t be as thick as a full-on cycling chamois due to the added bulk on the run, but it does need to provide adequate support and separation from the saddle.

Different brands are using everything from a thick-floaty-pull-buoy pad, to a thin strip of polyester fleece, or even no chamois at all for many of the elite athletes racing up to Olympic distance. Our Lava collection uses a thicker, multi-density long-distance tri chamois by Italian manufacturer Cytec for added comfort in the saddle. Where-as the shorter distance Aquaflo+ uses our ‘Tri-lite’ made to measure race-specific triathlon pad with fine-line stitching to further reduce any irritation. The lighter pad helps minimise water absorption while providing protection during the cycling phase, without impeding your swim or run.

Run–Support and Compression

As with swimming, a well-designed tri suit with compression in the right areas will support your core and running efficiency, reduce muscle damage and delay fatigue – important for that sprint finish!
Women might need some additional support in extra areas, so our tri suits all contain inner support for ladies. These are made from a higher denier strength lycra fabric to ensure comfort. The inner bra allows you to use the main zipper on the front to help you stay cool.


We’ve all experienced chaffing or irritation during a triathlon. The main culprits are body shape, suit fit, temperature, and moisture. While a suit can’t change your body shape and the fit will always be an individual thing, a suit which wicks moisture away from the skin and dries quickly will give you the best chance of staying comfortable throughout your race.

The Aquaflo+ collection uses a material called ‘Revolution-X’ which is the latest generation of tech-fabric made in Italy. It’s used on the back panels as it is very lightweight, offers 360-degree stretch and is extremely breathable.

Run–Temperature Control

Temperature control is key when racing so consider things like zippers and fabric. You can get both front and rear zippers but if you go for a rear zip, attach an elastic cord to the end of the zip so you can reach it when it comes time to open.
Hydrophobic, moisture wicking fabrics help maintain optimal body temperature in both hot and cold conditions. In hot conditions, it facilitates evaporation which removes heat from the body. In cold conditions, it pulls cold moisture away from the body, reducing the amount of energy required to stay warm.


In a shorter race you shouldn’t need to carry any gear or nutrition, but in a long course race, you may need pockets.

Avoid large, billowy pockets – these create drag and encourage you to carry too much stuff. Smaller pockets located on the back or side of your top and on the legs of your shorts are much more practical. We have thought about this and positioned pockets in all our tri suits. The activate tri suit, designed for shorter distances, contains a little pocket at the back.

Whereas the Lava range is designed for long distance so contains pockets on each side of the legs plus a larger pocket at the back, giving you enough space to carry sufficient nutrition throughout the race.
For Ironman or other very long races, also consider a nutrition belt or a race belt either with loops for holding your gels or a pocket – we have a Lyrca or neoprene pouch option.

We have something for every ability in our triathlon kit range that will help you reach new limits this season! To shop online, visit!



  1. Very useful thanks. I sized up when trying on not exercising having been used to looser fitting clothing. I thought the zip shouldn’t be pulling the material in should it? (Even my “compression” tops are perhaps too big then, oops, but they’ve worked well). Then found the zip came pretty close to my throat and any feeling of tightness disappeared as soon as I started moving. So may need to try what to be fair would be the right size based on my measurements and accept it’s a little tighter than I’m used to when putting on.

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