How Long is Ironman? A Look at How the Ironman Distance Came to Be

This article originally appeared on Triathlete

We've all been there: You tell a non-triathlete friend or family member that you're training for a triathlon, and you get the following questions: "You're doing an Ironman? That one in Hawaii? It's how many miles?!"

Of course, not all triathlons are Ironman races and you can be a triathlete without ever doing an Ironman brand or iron-distance race. Any multisport event consisting of swimming, biking, and running is a triathlon. Basically, an Ironman is a triathlon, but a triathlon doesn't have to be an Ironman. Still, there's something that draws people to the epic nature of the Ironman distance and can make it synonymous with the sport in popular culture.

How was the Ironman distance established? It all started back in Honolulu in 1978 with the inaugural "Hawaiian Iron Man Triathlon." Then, in 1980, ABC's "Wide World of Sports" brought coverage of the race into living rooms around the world. Since then, Ironman triathlon has conjured up images of swimming 2.4 miles in the aquamarine waters off Dig-Me Beach, biking 112 miles through the black lava fields down Queen K Highway, and running 26.2 miles in the brutal heat of the Energy Lab in Kona, Hawaii.

How did that Ironman race come to be?

The history behind the Ironman distance

Many different stories have circulated over the past 44 years about the origin of the Ironman distance. Some say it was a drunken bet or a masculine test of will. But the only way to separate fact from fiction, especially when it comes to the details of the original course, is to go straight to the source: John and Judy Collins.

In 1974, the Collins family participated in the Mission Bay Triathlon in San Diego, one of the first early triathlon events in the world. They enjoyed it so much they proposed an idea to their local swim club coach and, in 1975, the first Coronado Optimist Club Triathlon was held. It's now known as the longest continuously running triathlon in the world.

After the Navy sent the Collins family to Hawaii, they joined the Waikiki Swim Club and participated in the Waikiki Rough Water Swim--which is actually 2.385 miles. They also joined the Mid-Pacific Road Runners Club and ran the Honolulu Marathon. Enjoying these events, they wanted to create a long distance triathlon on the island, but they were missing one thing: the bike leg. An avid cyclist, John suggested a third annual event, the Around O'ahu Bike Ride (originally 115 miles and held over two days). So, how did the Ironman bike distance get shortened to 112 miles?

"We were thinking you could compete around the entire island by starting the swim at Kapiolani Park and then bicycling counter-clockwise to the start of the Honolulu Marathon by cutting three miles off the estimated bike route distance," Judy Collins said. "It was a perfect fit and a wonderful moment to figure that out."

Thus, the distances for the first Hawaiian Iron Man Triathlon were set.

Judy and John included a handwritten note on that first course description that read: “Swim 2.4 miles! Run 26.2 miles! Bike 112 miles! Brag the rest of your life!” The event would be the first triathlon in Hawaii and the first long distance Ironman triathlon in the world.

While many are familiar with these distances today, there's one important detail not many people know. "The best part of it, for me, was that when we added up the three distances, we realized it would equal 140 miles, which is the run perimeter of O'ahu," Judy said. "That always made it special that the mileage was equal to circumnavigating the whole island. It turns out that not many people knew that once the race moved to The Big Island."

RELATED: The Origins of Ironman: How Kona Became Kona

How far is an Ironman?

These days, you can find Ironman and iron-distance races around the globe, from France and Queensland to Alaska and New York. Some have ocean swims, while others take place in a river or lake. There might be a hilly bike course combined with a flat run course, or vice versa. But while the incredible destinations may vary, the distances remain the same.

For a full Ironman or iron-distance triathlon, athletes begin with a 2.4-mile swim, continue to a 112-mile bike ride, and finish with a 26.2-mile run.

However, it's important to remember that while the term "Ironman" is commonly used to refer to a specific distance triathlon, it is also the name of a branded race company. The Ironman brand also puts on shorter Ironman 70.3 races (also known as a half-Ironman). These races cover half the distance of a full Ironman with a 1.2-mile swim, 56-mile bike, and 13.1-mile run.

Also, there are iron-distance events that cover the same mileage, but don't fall under the Ironman brand of races. Examples include popular events like Challenge Roth and the extreme Norseman Tri, where athletes cover the same epic distances but without the Ironman moniker.

For exclusive access to all of our fitness, gear, adventure, and travel stories, plus discounts on trips, events, and gear, sign up for Outside+ today.