Swimming strokes in triathlon: the rules deciphered!
Swimming is considered the easiest part of triathlon by most people. But for beginners, it can be quite scary if they are not very confident swimmers. Especially with open water swimming, it can be easy to freak out during the race and struggle to breathe. This is why people generally wonder if they have to swim freestyle or if they can use another stroke during a triathlon.
Let’s see what swim strokes are allowed in triathlon, in which context, and if they are any exceptions.
Do you have to swim freestyle in a triathlon?
You are not required to swim freestyle in a triathlon. All strokes are accepted in the rules, and you can switch strokes at any time during the race. Generally, people prefer freestyle as it is the fastest and most efficient stroke. If you don’t feel comfortable with it, just use another stroke.

So freestyle is fast and efficient but for beginners, it can be more difficult to swim than breaststroke, which is generally learned at a young age. So feel free to use the stroke of your choice. I recommend you always try to swim freestyle at first to get used to it and slowly improve your ability. But when you start struggling, or if you feel like you are using too much energy, then switch to another stroke you feel comfortable with. It’s ok to change several times if you need to. With time and lots of practice, freestyle should become much more efficient than any other stroke and be the best choice to get a new PR.
Also, have you ever noticed that with the adrenaline of the race, and the number of people fighting in the water, it is very difficult to keep a steady breathing?
For instance, when I train I am breathing on alternative sides, every 3 strokes. During races, I have to breathe every 2 strokes for several minutes until things get quieter around me and I manage to get my heart rate down.
Thus, you might also wonder if you can use a snorkel while swimming freestyle in a triathlon. I have got you covered in this article:
Can you swim any stroke in a triathlon?
You can swim any stroke in a triathlon. World Triathlon and Ironman rules all approve the use of any stroke in competition. As long as you follow the correct swim course, you can propel yourself the way you want.
Indeed, according to World Triathlon – the international governing body for triathlon (previously named the International Triathlon Union ‘ITU’ before October 2021) – it is clearly stipulated that you can use the stroke of your choice in a triathlon:
“Athletes may use any stroke to propel themselves through the water. They may also tread water or float. Athletes are allowed to push off the ground at the beginning and the end of every swim lap.”
World Triathlon Competition Rules
If you race with Ironman Triathlon, their official competition rules do not specify any swim stroke for the race. This means you can use any stroke.
So to follow the rules:
- Make sure to follow the swim course
- Propel yourself with the stroke(s) of your choice (yes you can change at any time during the race)
It’s ok to take a break if you need to during the swim leg. There are a couple of rules to follow so you don’t get a penalty. You will find them in this dedicated article I wrote:
Is it ok to do breaststroke in a triathlon?
You can do breaststroke in a triathlon. Indeed, the rules allow you to swim any stroke. Breastroke is usually easier for beginners, and can be used also as a secondary stroke once you get tired or out of breath with freestyle.
Breastroke is generally learned before freestyle and if you are new to triathlon (or swimming) using breaststroke could be faster than freestyle. Indeed, freestyle is very technical and if you are not natural at it, it can take years of practice to master. At first, freestyle can be very tedious, especially with breathing. So don’t worry, you don’t have to use freestyle in a triathlon if you don’t feel like it.
Just a heads up: breaststroke uses the legs much more intensely than freestyle. Be careful to still have the legs to carry on with the bike and the run legs afterward.
Can you backstroke in a triathlon?
Triathlon rules allow you to swim backstrokes during a race. However, it is mandatory that you follow the prescribed course, which can be difficult to achieve in backstroke. You will have to check regularly not to miss a turn, or else you might risk a penalty.
I have gathered below an extract of the rules from the most common triathlon competitions. If you wonder why I am not quoting USA Triathlon (USAT), it’s because they are under World Triathlon and follow their rules (with a few exceptions but not about swim strokes).
“Athletes must follow the prescribed swim course”
World Triathlon Competition Rules
“It is the sole responsibility of each athlete to know and follow the prescribed swimming course. No adjustments in times or results will be made, for any reason whatsoever, for athletes who fail to follow the proper course.”
Ironman Competition rules
Can you swim butterfly in a triathlon?
You can swim butterfly in a triathlon. Any stroke is accepted by the rules. Butterfly can be really fast on short distances but it takes more energy than any other stroke. Be careful not to put yourself in the red so early in the race.