Why Is the Run at The End of A Triathlon? How Hard Is it !

The sport of triathlon will soon be celebrating its 50th anniversary. In honor of that milestone, let’s look back at the origin of the sport. Somewhere around 2 million people take part in triathlons around the globe each year. In addition to the origin story, this article will discuss the three sports involved in a triathlon and provide some reasoning behind their arrangement in the event.

I’m sure many triathletes have wondered why the legs of the race occur in the order that they do. One question that I know I’ve asked myself as I am struggling to make my legs move during the final miles of a triathlon is:

Why is the run at the end of a triathlon? Having the run at the end of a triathlon is more of a process of elimination. Choosing the swim for the last leg could be a dangerous proposition due to the higher risk of cramping, drowning, or other difficulties brought on by exhaustion. Finishing on the bike could lead to clusters of cyclists crossing the finish line together, causing mass confusion and a potentially dangerous situation. Eliminating the other two sports leaves running as the best option for ending a triathlon.

What is Brick Training in Triathlon? Why Do It!

Coming off the bike and transitioning into the run can be tricky for those who are new to the sport. After spending a significant amount of time in the saddle and turning the pedals at a high rate of speed, many people find that their legs feel wobbly and weak.

The best way to combat this jelly-legged feeling is to train for it. Completing several “Brick” workouts which combine biking and running, will help your legs and mind to overcome the transition from one sport to the other. [source]

For more on this, we highly recommend that you check out our post “What Is Triathlon Brick Training? Why You Should Do It & How!

What Is a Reverse Triathlon?

Just like it sounds, a reverse triathlon is an event where athletes start off with a run, then complete a bike ride, and finish the race in the water.

These quirky events are rare and usually limited to shorter sprint distances to ensure the safety of the participants. There are thousands of typical triathlons taking place every year throughout the world.

Organizers of reverse triathlons usually do it to help their event stand out from the crowd. Doing the events in reverse gives athletes the chance to try something a little different while still completing the same sports they are comfortable with.

Which Triathlon Leg Is the Hardest?

Each segment of triathlon comes with its own challenges. Most triathletes tend to have the most trouble with either the swimming or the running portion, depending on their training background.

The swimming segment is the smallest percentage of the race but can be very intimidating due to the mass start and the limited visibility.

The bike segment is the largest percentage and can easily use up a massive amount of an athlete’s energy store if they don’t pace themselves correctly. The run comes at the end and has the highest level of impact on a body that is already fatigued due to the prior efforts of swimming and biking.

Personally, I find the swim to be the hardest part of a triathlon. Even though I was on the swim team for a few years when I was younger, I still never feel very comfortable in the water. I am much more at ease while either running or riding a bike. I am thankful that the swim segment is first because I can feel a huge sense of relief when it is over and I can move on to my preferred sports.

However, there is more to what is considered the hardest part of triathlon. For more on this, check out our post “What Is The Hardest Part Of Any Triathlon? Here Is The Most Important Thing To Do !

Which Leg Is the Easiest?

Many people find the bike leg to be the easiest segment of a triathlon. Even though it is the largest part of each race, biking takes less energy than the other two segments.

There are often times during the bike segment, especially on downhill sections, where it is possible to simply sit and rest while still moving along at a fast pace.

That sort of active resting is never possible during the other two disciplines. Triathletes will often take advantage of those windows of opportunity to drink and eat to replenish their body’s energy.

On the other hand, the bike is also the segment where many problems can arise that are out of the athlete’s control. Modern triathlon bicycles are complex machines with numerous moving parts, some of which are quite delicate.

Tire punctures, broken chains, and even more severe mechanical issues are possible during any bike ride. Punctures can be easily dealt with, but anything beyond that can mean the end of the race for the unfortunate athlete who’s bike has malfunctioned.

What Is a Duathlon?

Duathlons are races that combine both running and cycling. Most of these events have 3 segments – running, cycling, and then running again.

Duathlons have been taking place even longer than triathlons have existed. They may even have been part of what inspired that original triathlon so many years ago. The duathlon is very similar in format to the triathlon, and should not be confused with the “biathlon.”

The biathlon is a completely different event that combines cross-country skiing and target shooting. Duathlons are great for people who don’t want to or can’t get into the water for a swimming segment.

For more on duathlon, check out What Is A Duathlon? Distances, Order, Gear, How To Train & Beginner Tips

There’s also a more recently developed event known as the aquathon, which combines swimming and running. One of the more popular of these events is the Frogman Swim/Run that is held each year in Jenson Beach, Florida. (Source)

Are There Multi-Sport Events that Don’t Include Running?

Aquabike is a Multi-sport that does not include running. This style of event combines just the first two disciplines of the triathlon, the swim, and the bike ride.

In fact, many aquabike events actually take place at the same time as the full triathlon. Competitors who don’t wish to or are unable to complete the run can register for the aquabike and simply stop their event after finishing the bike segment.

These are great opportunities for an athlete who has a running-specific injury but still wants to be able to compete.

Who Decided on The Triathlon Disciplines and Order?

Jack Johnstone & Don Shanahan invented the sport of triathlon in 1974. The two friends were members of the San Diego Track Club and had an idea for this new type of event that combined 3 separate sports.

The first-ever triathlon was held in the evening, and the 46 participants were asked to complete 2 swimming segments, 1 biking segment, and 2 runs. Even though the first-ever triathlon was not well organized, it was still well-received.

Different versions of the triathlon started to take place around the San Diego area. Eventually, it was transformed into the Swim-Bike-Run format that we know today. [source]

Four years later, two of the participants in that first triathlon came up with an even more challenging version of the event.

John and Judy Collins had moved to Hawaii and were endurance sport enthusiasts. They dreamed up a race that would combine three of Hawaii’s most challenging events – the Waikiki Roughwater swim (2.4 miles), the Around Oahu Bike Race (112 miles) and the Honolulu Marathon (26.2 miles). John announced that whoever finished the race first would be called the “Iron Man”.


So there you have it – now you know why running is the last segment in a traditional triathlon. But why limit yourself to the traditional format, when there are so many alternatives out there to choose from? Pick whichever format fits your personal athletic style the best, and be sure to give it your best!

Brad Birky

Brad Birky is an endurance athlete and trained chef who has qualified for and completed the Boston Marathon as well as multiple Ironman distance triathlons

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