The Three Sports Of Triathlon And Their Relative Importance

When I speak about triathlon with my colleagues, someone always asks me what the three sports are. I thought I would write an article for anyone who has the same question and who knows, might become a future triathlete!

A triathlon is a single event that combines three sports one after the other: swimming, cycling, and running. The transitions between each sport are often referred to as the fourth sport in triathlon. Depending on the type of triathlon and its distance, one discipline might be more important than the others.

After finishing dozens of triathlons, I realized that it is not always the same sport the most important one. Let’s check that in more detail.


In almost all triathlons, the order will be the same: swimming, cycling, and then running. If you ever wondered why, have a look at this article from my wife: 7 Reasons Why The Triathlon Order Is Typically Swim-Bike-Run

The dynamic of the race is, however, completely different whether the organizers allow drafting on the cycling portion or not:

  • By drafting (think Tour de France riders who ride behind each other to save energy), the swimming portion and the first transition become extremely important. All triathletes would prefer to be in the front cycling pack and potentially save some energy rather than spending time chasing. You will often hear commentators say that you can’t win a triathlon on the swim, but you can lose it.
  • The non-drafting triathlons force triathletes to maintain a distance between each other on the bike (generally between 10 to 20 meters depending on the race). Triathletes who are not respecting this rule receive a time penalty.
    In non-drafting triathlons, the swim is not as critical.

When looking at races, the organizers will always state if drafting is allowed. It is typically used for elites triathletes on short-distance triathlons. 


Another important distinction in triathlon is the environment of the race. Here is a quick comparison of what you can expect:

SportRoad TriathlonCross Triathlon
SwimPool or open waterPool (rare) or open water
BikeRoad (Triathlon bikes, road bikes,
and MTB are generally allowed)
Mixed Terrain (MTB only),
can be really technical
RunOften roadOften trails

Even if they are both referred to as triathlon, I personally find the effort to be really different. In road triathlons, my heart rate is relatively constant, whereas my heart rate is jumping all the time on the bike and run portions of cross triathlons.

From my personal experience, if a race organizer is labeling its cross triathlon as family-friendly, it doesn’t necessarily mean it will be an easy course! 😉


Apart from the Ironman branded events which have the same distance, all other triathlons can vary in length. In the table below, I summarized however the most common triathlon distances (swim-bike-run):

FormatDistances (mi)Distances (km)Also Known As
Full distance2.4-112-26.23,8-180-42,2140.6, Ironman, XXL
Half distance1.2-56-13.11,9-90-21,170.3, Half Ironman, L
Olympic0.93-24.8-6.21,5-40-10Standard, M
Super Sprint0.25-6.2-1.60,4-10-2,5XS

In previous articles, I have analyzed the average time a triathlete needs to finish a race. Looking at those data, I found particularly interesting the weight of each of the four sports depending on the distance. As you can see below, the shorter the triathlon is, the more time triathletes will spend in the water and in transitions (relative to the total time)!

Weights are based on 2019 races for the full Ironman distance,
and on one representative race I picked for all the other distances.

If you want to have more details on the time, you can check the following articles:

I hope this article helped you better understand the three (or should I say four?) sports of triathlon and how important each sport is. Now, let’s get back to training.