The Most Important Swim Rules In Triathlon

I couldn’t swim more than 50m freestyle when I started triathlon. So, learning that I could swim breaststroke during races was a big relief. Even if you are an experienced triathlete, I bet you don’t know some of the following rules or you didn’t know that they can vary by country.

I have checked the latest official rules from the ITU (International Triathlon Union) as well as the ones from the 3 biggest national federations: the USA (USAT), France (FFTRI), and Great Britain (British Triathlon). Not all triathlon races are governed by those federations but most of them are following those rules anyway. Always check your particular race.


All swimming strokes are allowed by the ITU and the USA Triathlon. Backstroke is however forbidden in Great Britain for any pool swim. For open water triathlon, athletes must inform race organizers before the race that they wish to use backstroke. Nothing particular about the strokes is mentioned in the French rules. Drafting in swimming is allowed as long as you are not touching repeatedly other athletes. 

Freestyle remains the most efficient stroke for triathletes but like me, you might be happy to know that you can switch to breaststroke when needed. I used it quite often in my first triathlons when I was tired and also to bring me back in the right direction. I haven’t seen anyone do butterfly until now, I wonder why… 😀

If you are swimming breaststroke, be aware that you will need more space around you. Just swim a bit on the side of other triathletes. Speaking from experience, receiving a kick from someone doing breaststroke can be really painful. As long as you are not voluntarily or repeatedly touching other triathletes, you should not worry too much about it. Otherwise, it may lead to disqualification.


The ITU and the three national federations (USA, France, and Great Britain) authorize you to rest by standing on the bottom or by holding to an inanimate object (ex: buoys, stationary boats, floating objects). You should not make forward progress.
However, if you request assistance (by raising an arm overhead), you will need to retire from the race.

I was actually surprised when looking up this rule. I always thought that resting would automatically lead to disqualification. If you have friends which are afraid to take part in triathlon because of the swim portion, make sure to mention it.


Freestyle swimming with a wetsuit will (almost) always make you faster. The extra buoyancy that you gain from the neoprene will lift you higher in the water. You will save energy and your legs will be fresher for the bike and run portion. 

I personally disliked swimming breaststroke with a wetsuit, my legs were often too high in the water or even outside of the water. I somehow compensated for it with my back which gave me back pains. Make sure you try it before your race.

Also, consider the time it might take you to remove it during the transition, beginners might be better off swimming without one for really short distances (Super Sprint or Sprint).

Depending on the temperature of the water, the decision of wearing one or not might be taken by the race organizers. Please note that the wetsuit should not be thicker than 5mm. Here is a summary per federation for age groupers:

Wetsuit use for ITU triathlons:

Swim Length:Wetsuit Mandatory:Wetsuit Forbidden:
up to 1500m15.9°C and below22°C and above
1501m and longer15.9°C and below24.6°C and above

Wetsuit use for USAT triathlons:

Wetsuit Forbidden
(for age-group athletes eligible
for prizes and awards):
78°F or above
Wetsuit Forbidden:84°F or above

Wetsuit use for triathlons in France (FFTRI):

Swim Canceled:< 12°C
Wetsuit Mandatory: < 16°C
Wetsuit Forbidden:> 24.5°C

Wetsuit use for triathlon in Great Britain (British Triathlon): 

Swim Length:Wetsuit Mandatory:Wetsuit Forbidden:
up to 1500m< 14°C> 22°C
1501-3000m< 15°C> 23°C
3001-4000m< 16°C> 24°C


If a swim cap is provided by the race organizer, which is the case in most triathlons, it is mandatory to wear it. Altering it in any way may result in a penalty up to disqualification. If triathletes want to wear a second swim cap, it should be worn under the official one.

In all triathlons I have been part of, the swim caps were provided by the race organizers. You might see different colors depending on the swim waves (female/male, distances). It might be demoralizing to see swimmers from other groups taking you over but at least, you are aware of it and you know that more athletes are coming 🙂

Some triathletes like to wear their swim goggles under their swim cap to avoid losing them.


As a general rule, all equipment that is helping your propulsion or your breathing is forbidden. Here is the full list of illegal equipment from the ITU:

  • Artificial propulsion devices
  • Flotation devices
  • Gloves
  • Socks, except when the use of wetsuits are mandatory
  • Wetsuits or any part of the wetsuits when they are forbidden
  • Non-certified swimsuits
  • Snorkels
  • Official race numbers (in non-wetsuit swim only)
  • Headphone(s), headset(s) or technical earplug(s), which are inserted or covering the ears, except ear protection plugs;
  • Safety inflatable device (tube) which has been deployed. If deployed the athlete must retire from the race.
  • Any jewelry deemed to be a hazard to themselves or other athletes (Athletes may be requested to remove any such items.)

This list is mainly common for all three triathlon federations. The biggest difference is with the use of gloves in the USA which is allowed under certain conditions:

When wetsuits are mandatory, gloves may be worn, but must not aid in propulsion (no swim resistance gloves, hand paddles, webbed gloves or web like construction between the fingers). The Head Referee may inspect gloves to determine compliance with this rule.

Article 4.7.f   Competitive rules, USA Triathlon

Funny enough, swimming goggles or masks are not mandatory items but I don’t see how you could do without them.

Use those rules as general guidance. Make sure to always check the rules of your specific races. You can be sure that extreme events like the Norseman or Patagonman have different rules, especially on the equipment side (thickness of neoprene, neoprene cap, gloves, and so on…) That’s not to confuse or annoy triathletes, it is really for your safety.

If you realize (before I do) that any of those rules changed, please email me at