Why Does Triathlon Start With Swimming? How Risky Is It!

Due to my expertise in running, I would prefer to lead off triathlon with running then end with cycling or maybe swimming. But we all know it’s not the traditional sequence for triathlon events.

The article provides all the facts yet some opinions to answer a very prevalent question, why does triathlon start with swimming? 

The traditional sequence is not scientifically verified but has more authenticity than any other event sequence. The first and foremost reason for the widely adopted sequence is the enhanced safety it offers, which has more of a logical hypothesis.

The event organizer carries this as a crucial responsibility, and they left no ground to overlook this cause.

If it would be a second or third sport in the sequence, the triathlete can drown due to reservation. triathletes should begin the swimming leg when he/she is in high energy. (Source)

In short, the major reason behind this is safety.

Asides from safety, many other factors such as transition time management contribute to the purpose why triathletes start with swimming. To help you with transition time management, read through this article on the must-have triathlon transition checklist.

Also, if the swim is your biggest concern, did you know you do not have to freestyle it. Check out our article about Do you have to swim freestyle in triathlons? Better Alternatives!

And if you intend to get into open water swimming then make sure to go through How Dangerous Is It To Swim Alone? Must-Know Risks & Precautions For Openwater Swimmers

Let’s dive deep into answering this question further by explaining the traditional event sequence, why swimming is placed first, and other important information you should know as regards the triathlon event sequence.

What is the traditional event sequence?

The conventional events sequence for the triathlon is Swimming>Cycling>Running. However, for the reverse triathlon, the sequence is reversed.  Check out this article for more details: What Is Triathlon Order? Hardest Part And Why Start With The Swim!

Triathlon is a multisport competition. The sequence of events is followed by the triathletes, which are announced officially by the event organizers. The triathletes prepare themselves before the event day. The event may follow a traditional, reverse, or a sequence of the triathlete’s choice.

A review added at Quora will help you know the experience of an athlete who chose to try a random sequence triathlon

I did a race last summer (sprint distance) where the organizers let everyone start with whatever leg they chose. It went remarkably well (and, believe me, you are plenty exhausted by the third leg, regardless of the race distance – this one was a sprint.)

The main drawback, I’d say, is logistics, not safety: you need to keep course marshals out on the water for the entire duration of the race to accommodate people who choose to swim last. Ditto the bike and run courses. So, more staffing is needed. (Source)

Rachel Biederman

Is it necessary to follow the traditional sequence of Swimming>Cycling>Running?

Is it necessary to follow the traditional sequence of sports, and why? No, it is not. It is just a matter of tradition, safety, and convenience. 

Despite swimming being the first leg in triathlon, it involves more risk than in cycling and running. Consequently, it’s less detrimental to end triathlon with running or cycling than to end with swimming.

However, the traditional sequence is not scientifically verified but has more authenticity than any other event sequence. First and foremost, it offers more safety, has more logical reasons, last but not the least, it’s standardized.

A triathlete should necessarily be more adaptable to this order, to avoid consequences that may occur otherwise.

I do see many of the beginners who favor cycling to be the last sport in this competition. And therefore, a question may arise,

For more details, check out our article on What Is The Order Of Triathlons? Hardest Part And Why Start With The Swim!

Why Does Triathlon End with Running and Not Cycling?

The main reason again is safety. You must be cognizant of the accidents that have usually occurred during cycling in Tour de France. A logical explanation can help you understand why that is so.

The athletes try their best to achieve the goal under the wire which involves a lot of endangerment and risk in the final sprint.

And that is why it’s safest to end triathlon with running. Also, you should know that an exhausted runner who stumbles can be at less risk than an exhausted cyclist who falls over.

How Many Transitions Are There in Triathlon?

Two transitions occur during the triathlon. One occurs when an athlete exits the water and puts on bike gear. The second transition occurs before running.

With this thought, the second doubt was to know about the change in transition timing with the difference in order and if a change in sequence can impact the transition time? 

Yes, for each sequence there are differences in timing, and they affect the transition time. But How?

If we talk about swimming as the second sport in the event. The time required for a triathlete to put on a wetsuit and again taking it off before the final sprint can increase the transition time. Secondly, it will be challenging to put on a wetsuit on a sweaty body than a dry one.

Unfortunately, no empirical data is available to know when it’s most suitable to take the wetsuit off. However, the physiological cost of running while wearing a full wetsuit or not, or halfway down explained hypothetically in an article which says, (source)

It was hypothesized that running without the wetsuit (i.e., not carrying or wearing it in any way) would result in the lowest physiological cost while running with the wetsuit halfway down would be the least time-consuming.

Can a change in sequence impact the performance?

Yes, it can. Earlier I talked about the reasons why we should follow the conventional sequence in triathlon, though it has some drawbacks as well. You may wonder why is the sequence swim-cycle-run. Apart from safety, performance is another cause.

What Are Some Reasons Why Triathlon Starts with Swimming?

I have emphasized so much how safety is the major reason why triathlon sports begin with swimming. But, here are other reasons why this might be so.

To make the triathlon sport more spectator-friendly

The triathlon sport should begin with the swim leg because it makes it better for the spectators to understand the progression of the sport. This makes sense because if the swim leg was to be placed last, it will be difficult for the spectators to see who might be leading during the race.

To avoid any form of competition with wearing a wet suit

It’s not so easy to put on a wet suit especially when the swim leg is performed in open water. For this reason, if the swim leg is placed as the second leg or third leg, it would be more difficult to put it on. This is because you would find yourself all sweaty and exhausted from previous legs to do so.

The ability of the triathletes

Most triathletes aren’t fans of swimming, just a few are. For this reason, it is placed first, where it can be done and gotten over with.

Easier control in water

It is easier for the lifeguards to have control of the swimmers with swimming as the first leg. This is because at the start, everyone is seen in the water at the same time without having some on land and some in water. Imagine if swimming was the second and bike the first, you might have some triathletes still on the bike while others are in the water, which will cause a lot of confusion.

Is there any drawback to putting the swim leg first?

Yes, there is a drawback. As the first event in a sequence, there will be many athletes swimming at the same time. So, It’s difficult to notice a swimmer who is in trouble. 

However, if it is placed in the last or second place, the athlete might drown from exhaustion. Or, it might get a bit difficult to swim with tired muscles. In this way, it can affect the level of performance. Also, the increase in transition length could occur if you chose to swim in second place.

To manage the drawback that comes with the swim leg being first, a more attentive staff should be put in place to notice any mishap that might occur, and a rolling start also helps.

Risk level of Triathlon Swim Leg

Swimming involves more risk than any other sport in triathlon. Most of the deaths have occurred while swimming. The most common cause of death in triathlon is heart abnormalities. The chances of drowning from exhaustion are more common.

Although the swim is the riskiest discipline in any given triathlon race because it’s where most fatalities happen, it is still considered an extremely rare event. The risk is around 1.7 per one hundred thousand people, which is around the same likelihood of getting struck by lightning which is around 1 in 80,000 (Source).

On a side note, If you wear glasses, consider using prescription goggles. Check out our post on How Much Does Prescription Swimming Goggle Cost? Types and How To Pick One

A research was conducted to know the main cause of death. The researcher answered some questions shedding light on why deaths still occur during swimming events.

He gave four major reasons why this occurs: (Source).

  1. Death could occur due to the high number of triathletes entering the water at the same time and the adrenaline surge that occurs as a result of this.
  2. Most of the triathletes are not well grounded in swimming compared to running and cycling.
  3. The swim leg in triathlon is a lot different from other swimming events as it involves a lot of waves as well as people swimming so close to one another
  4. While swimming during a triathlon, it is not easy to take breaks as you would do while cycling or running.
  5. There is great difficulty with noticing a triathlete who might be in trouble while swimming due to the number of triathletes in the body of water.

Also, we highly recommend that you check out our post “Why Do Marathon Runners & Triathletes Collapse? (Risks & Prevention Tips)

How to Ensure Safety on The Swim Leg?

Don’t risk your life. Safety should always be your first priority. so, you should:

This video can help you know the basic skill set required while swimming.

Organizers are advised to properly evaluate participants before the start of any event.


The final thoughts revolve around the fact that though Swim-Cycle-Run is not necessarily described as the official sequence, yet, it is safer than any other sequence, with the swim leg being the first. Regardless of the drawback that comes with the swim leg being the first, it still ensures the optimal safety of the participants.

Deaths have occurred even in the events following the traditional sequence but it is very very very rare. The training and awareness of safety measures shrink the risk even further.

Also, consider checking our post on Are Triathlons Harder Than Marathons? Alternatives & Why To OR Not To Race One


An extreme triathlete who have competed in dozens of triathlons including IronMans and Extreme triathlons.

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