The Ironman Wetsuit Rules + Temperature Cutoff Explained

Can you wear a wetsuit in all triathlon competitions? Keep reading to find out.

The use of wetsuits in a triathlon can keep you warm and increase your buoyancy, thereby making the swim easier. 1Gay, A., Ruiz-Navarro, J. J., Cuenca-Fernández, F., López-Belmonte, Ó., Abraldes, J. A., Fernandes, R. J., & Arellano, R. (2022). The Impact of Wetsuit Use on Swimming Performance, Physiology and Biomechanics: A Systematic Review. Physiologia2(4), 198–230. https://doi.org/10.3390/physiologia2040016

‌But there are Ironman triathlon wetsuit rules, and not all triathlons are wetsuit-legal. This means you can’t always wear a wetsuit in the race, depending on the specific triathlon rules and the water temperature.

Keep reading as we discuss whether or not you should wear a wetsuit in a triathlon, the Ironman legal wetsuit temperature, and other triathlon and Ironman wetsuit rules.

We will cover: 

Let’s jump in!

People in wetsuits running into the water.

Should You Wear a Wetsuit In a Triathlon?

One of my favorite stories that I like to relay to my first-time triathletes who are anxious about their first race is about my own first triathlon.

 I decided I wanted to compete in an Olympic distance triathlon, so I trained myself by creating a training plan and adding bike and swim workouts to supplement my running training.

I was already running long-distance races, so the 10k run segment of the Olympic distance triathlon would be no big deal. I was also a pretty avid recreational cyclist, so I was not overly concerned with the 40k bike portion of the race.

However, like many novice triathletes or prospective triathletes, I was exceedingly anxious about the swim.

If you have a background in swimming, a 1500m swim may not sound like a big deal, but for people attempting their first triathlon, swimming nearly a mile in open water can be really daunting.

I had only had the opportunity to train in a swimming pool because I was living in New York City and couldn’t access open water swims.

People in wetsuits running into the water.

Therefore, I was going into the triathlon open water swim environment blind, so to speak.

I read that you could wear a wetsuit in the race, and I decided that that would be a good idea since I am very petite and always freezing in water.

I looked online for a triathlon wetsuit, but they were out of my price range at the time. Plus, because I am barely 5 feet tall and very slender, I decided I could save money and get a child’s wetsuit.

I ordered one online at a discount market, deciding to go with a child’s XL to ensure it would be large enough for an adult body (ring the ignorance bell!).

Of course, being the complete newbie that I was to the sport of triathlons, I didn’t know that there were key differences between a triathlon wetsuit and a wetsuit for kids who want insulation in colder water.

When my wetsuit arrived, I was pleasantly surprised (ring the novice triathlon bell yet again!) that the wetsuit was huge because this meant that it was easy to get on and off.

The little I had read about triathlon wetsuit tips and wearing a triathlon wetsuit was that it was notoriously difficult to get on and off.

Triathlon swimming tips even suggested using lube or asking volunteers to help peel the triathlon wetsuit off after the swim portion in transition one.

People in wetsuits running into the water.

That wouldn’t be a problem for me because my wetsuit was almost like a swimming bag, with tons of wiggle room in the legs, arms, and certainly the body.

Anyway, the day of the race came, but I had not had a chance to try the wetsuit in the swimming pool because it had arrived just in the nick of time (yet another mistake—not being able to try a key piece of my triathlon kit before ordering it so close to race day!).

When I lined up on the beach with other women in the 20 to 25-year-old age group, I noticed that everyone wore a sleek, well-fitting triathlon wetsuit while I was wearing what looked like a huge mascot costume of a scuba wetsuit.

When the horn sounded, and we ran into the water to begin the swim, I was immediately in trouble: the wetsuit filled with gallons of water and started pulling me under.

However, I was so overwhelmed by the sea of arms and legs kicking and splashing and swim caps pushing past me that I wasn’t sure what the problem was. 

Had I suddenly forgotten how to swim? Was I just getting trounced by better swimmers? Was I having an anxiety attack?

Within minutes, the entire wave of women in my age group was well ahead of me, and I was trying to get myself off of the sandy bottom of the lake and swimming forward, but I was being pulled down by what must’ve been 80 pounds of water inside of my wetsuit. 

People in wetsuits swimming.

I could barely breathe. I could barely move. I felt like I was going to drown.

Somehow, I swam to the first kayak volunteer and said: “I don’t think I can do this! I think I need to stop!“

However, I kept going and made it to the next volunteer, who told me there seemed to be an issue with my wetsuit. A lightbulb went off!

So, in the middle of the New York Sound, I somehow unzipped the enormous, waterlogged wetsuit and freed myself. 

The wetsuit was so filled with water that I couldn’t even lift it out of the water to give it to the volunteer in the kayak, but she urged me on and said to keep going.

I finished the swim in just my sports bra and triathlon shorts that were under my wetsuit, far behind all of the other women in my age group.

In fact, waves of other age groups started and passed me because I was not a very good swimmer, and by the time I finally got out of the water, I threw my arms up and triumphantly said: “I did it! “

Of course, I wasn’t so much proud of my swim time, but I was just relieved that I survived!

Needless to say, I learned quite a few lessons about the importance of getting the right wetsuit for a triathlon race, and I was humbled by my ignorance, to say the least!

People in wetsuits running into the water.

Of note, the rest of the Olympic triathlon was awesome: I was flying by people on the bike course, and running is my primary sport, but not knowing how to use a wetsuit in the triathlon properly certainly hurt my time and gave me an honest scare about drowning.

So, why do I explain such a long and self-indulgent story?

I often share this story with triathletes I coach who are nervous about swimming for several reasons.

  • For one, I think it helps people who are anxious understand that even more competitive triathletes have had bad races and started at the very bottom. 
  • It’s OK to struggle in your first race or come in last. Someone has to do it, and you can only go up from there!
  • It speaks to some of the key mistakes I made in getting a wetsuit for a triathlon and understanding the importance of wearing a wetsuit.
  • A triathlon wetsuit helps provide buoyancy and reduces the effort to swim.
  • It should be extremely tight and form-fitting so that you don’t have any of the water accumulation that I was having.

You should always try on your wetsuit before you buy it, and certainly give it a couple of test runs before race day, just as you would with running shoes, bike shorts, or any other important piece of triathlon gear.

A person fixing their swim cap.

Finally, practicing getting on and off your triathlon wetsuit is important, and it is also ideal to practice open-water swimming before race day if your triathlon event has an open-water swim. This will minimize the anxiety of swimming in open water. 

Moreover, it is great if you can practice swimming with other people in a crowd to replicate the mass start. 

Had I had experience with these factors, I would’ve been less anxious about them and would have been able to identify more quickly that the reason I was struggling was not because I was overwhelmed by being in open water or around hundreds of other women swimming on top of me, but because there was an issue with my triathlon gear itself.

What Are the Ironman Wetsuit Rules?

As per the official Ironman wetsuit rules, there are several Ironman triathlon wetsuit rules.2What are the wetsuit restrictions?  · Customer Self-Service. (n.d.). Help.ironman.com. https://help.ironman.com/knowledgebase/article/KA-01052/en-us

‌The wetsuit competition rules for Ironman triathlons and other triathlon races are subject to change, so it is always important to read the race rules for the specific Ironman triathlon or Ironman event you are participating in.

People in wetsuits running into the water.

Here are the current triathlon wetsuit restrictions:

#1: Wetsuits Thickness

What is the maximum thickness for a triathlon wetsuit?

Wetsuits can’t be more than 5mm thick.

Note that thicker isn’t always better. You will lose mobility in your shoulders, in particular, if the wetsuit is too thick.

You want to go with a thinner wetsuit or at least one that gives you the full range of motion unless you need added buoyancy. Weigh the pros and cons based on your own swimming weaknesses and fitness level.

#2: Ironman Wetsuit Legal Temperature Rules

At what temp do you need a wetsuit?

Professional triathletes and age group triathletes can wear a wetsuit if the water temperature is up to (and including) 76.1 degrees Fahrenheit (24.5 degrees Celsius) or colder, and you must wear a wetsuit in a triathlon swim if the water temp is below 60.8 degrees Fahrenheit (16 degrees Celsius).

Wetsuits are never allowed in water temperatures greater than 83.8 degrees Fahrenheit (28.8 degrees Celsius) for any athlete.

You will not be eligible for age group awards if you wear a wetsuit in the water temperature range of 76.2 to 83.8 degrees Fahrenheit (24.55 to 28.77 degrees Celsius).

A person fixing their swimming goggles.

#3: Permitted Wetsuit Types

As for swimwear, you can wear a sleeveless or full wetsuit with your arms and legs covered, but the De Soto Water Rover and the Speedo Elite Triathlon Wetsuit with forearm flaps wetsuits are not allowed. 

Race officials will publish the final decision about whether the triathlon will be wetsuit-legal on the morning of the event.

For best practices, it is always a good idea to check with the wetsuit manufacturer to ensure that the wetsuit is triathlon legal and/or reach out to the race directors of the specific triathlon event to verify that you can wear your wetsuit brand ahead of race day.

Of course, you will still be subject to Ironman wetsuit rules published on race morning based on the water temperatures. Be sure to check so you don’t risk facing disqualification!

If you are looking to start open-water swimming, check out:


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Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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