The start of an Ironman 70.3, or Half Ironman, men's race in Spain, May 2014.

The start of an Ironman 70.3, or Half Ironman, men's race in Spain, May 2014. Ironman triathlons consist of long-distance swimming, bicycling, and running races for both men and women, organized by the World Triathlon Corporation. Ironman 70.3 covers a total distance of 70.3 miles, while the traditional Ironman race covers 140.6 miles.


The purpose of the Ironman triathlon is to test the physical endurance and mental stamina of its athletic participants due to its grueling length (11 to 17 hours of constant exercise) and arduous race conditions (winds, waves, heat, and sometimes very inclement weather). The primary purpose of each Ironman competition is to complete the course in the fastest time, which includes timed transitions between the individual swim, bike, and run portions. Because of their popularity around the world, the various Ironman competitions have helped advance the sport of triathalon.


An Ironman race can be generally entered by anyone who is willing and able to swim, bike, and run the required distances and to do it all without any appreciable breaks (only transitions are allowed between the three events to change clothes and equipment). However, certain restrictions apply for entrance into the main Ironman World Championship; primarily, winning one of the preliminary events is the main requirement. In addition, entry fees are required for each preliminary event to the main championship race.


The Ironman competition was conceived in 1977 during the awards ceremony for the Oahu Perimeter Relay, which is a 134-mi. (216 km) running race around the Hawaiian island consisting of five-person teams. The first Ironman race was held on February 18, 1978, in Hawaii. At the start of the race one of the participants was noted to have said, “Whoever finishes first, we'll call him the Ironman.” Of the fifteen male participants, Gordon Haller (1950–), a U.S. Navy communications specialist, earned the title “Ironman” when he finished the race in 11 hours, 46 minutes, 58 seconds.

Over 90,000 athletes, both men and women, compete annually for slots in the Ford Ironman World Championship that is held every October in Kailua-Kona, Hawaii, and the Foster Grant Ironman World Championship 70.3 held every November in Clearwater, Florida. The events are considered by triathlon athletes as two of the most demanding endurance events in the world. Anyone, men or women, who complete an Ironman race within the time limit (generally, 17 hours) and according to the prescribed distance are entitled to call themselves the gender-neutral name “Ironman.” Specifically, in order to be considered an “Ironman,” most Ironman events start at 7 A.M. local time, and the participants must finish with the swimming portion by 9:20 A.M., the biking competition by 5:30 P.M., and the running part by midnight.

Athletes with disabilities also compete in Ironman events within a separate physically challenged category; however, each is expected to meet the same requirements as the non-physically challenged groups.

The Ironman World Championship in Kailua-Kona, Hawaii, involves:

Qualifying for the championship involves placing at a certain high-ranking positions within various preliminary Ironman races or, in some cases, finishing a race or winning a lottery. The preliminary races to qualify for the Ironman World Championship occur in many parts of the world. The following cities in North America hold preliminary competitions:

A substance that inhibits oxidation, the process of adding oxygen to a chemical reaction.
The acronym for deoxyribonucleic acid; the substance that carries a living organism's genetic material.
Relating to the thick muscular wall of the heart.
A substances that oxides another substance.
An athletic contest, usually involving swimming, cycling, and running, consisting of three separate events in which points are awarded for each, but an overall best athlete is awarded at the end of the competition.
Ventricular arrhythmia—
Abnormal heart rate or heart rhythm.

The following cities holding competitions in Europe are:

The following cities holding preliminary competitions in Australia and New Zealand are:

The following cities in Brazil, China, and South Africa hold competitions:

Amateur athletes are required to qualify through performance at any of the Ironman races or some of the Ironman 70.3 races (called Half Ironman races—consisting of a 1.2-mi. (1.9-km) swim, 56-mi. (90-km) bike ride, and 13.1-mi. (21.1-km) run. Entry into the Ironman can also be obtained through a random lottery or through the Ironman's charitable eBay auction.

Beginning with the 2011 Ironman World Championship race, a point system exists to qualify professional triathlon athletes for the Ironman World Championship. Professionals must earn points by competing in WTC-sanctioned Ironman and Ironman 70.3 events throughout the qualifying year. The top 50 male and 30 female professionals, according to total points accrued by the end of the qualifying year, are eligible to race in the World Championship. In addition, winners from earlier years receive an automatic entry for the upcoming Championship race for a period of five years after their last win, provided they compete in at least one entire Ironman race during the qualifying year.


Training for the Ironman requires preparing for long-distance competition in the three activities of swimming, bicycling, and running. Consequently, several years of basic aerobic training may be required before athletes can safely and effectively train for a triathlete competition such as the Ironman.

According to the website, many books are available that can help to achieve success in the Ironman competition. For instance, Starting Out by Paul Huddle and Roch Frey offers the basics, such as weight training, flexibility, and nutrition, necessary for training in swimming, bicycling, and running in a short-distance triathlon event. Also authored by Huddle and Frey, Start to Finish supplies more advanced information on triathlon distances such as those found in the Ironman. It details all the necessary information—including how to balance work, family, and training, along with the mental preparation necessary—for training in an endurance triathlon.


The Ironman is well known for its harsh conditions and its demanding length. Because of such issues, injuries are likely within its training and competition. Medical risks can develop for people who train for such long-duration events. For instance, a Belgium study in 2007, published in the European Heart Journal found that ventricular arrhythmia (VA) was present in 82% of such athletes. VA is a condition in which the heart beats at an irregular rate and rhythm.


An Austrian research team performed a risk assessment of Ironman triathlon participants in 2008. The principal investigator of the study, Dr. Karl-Heinz Wagner, along with his colleagues, studied detrimental and beneficial effects of prolonged, intense, and extraordinary exercise, such as that performed at Ironman competitions. They concentrated on the interaction between oxidants and antioxidants within the bodies of extreme performers and the link to muscle fatigue and damage and inflammatory and other stress responses. They also looked at the condition of DNA (deoxyribonucleic acid) during such strenuous exercise.

The Austrian research team found that significant inflammation occurred during and immediately after such races, but it subsided rapidly and disappeared within three weeks. Myocardial (heart) stress occurred and subsided in a similar way. Oxidative stress levels also rose temporarily but the study did not find any sustained oxidative stress levels. In addition, such levels returned to normal within five days.


To win, or even compete, in an Ironman event takes a persistent and dedicated training schedule that must focus on three types of exercise all at the same time. Because of the nature of such comprehensive training, Ironman competitors have overall exceptional strength and endurance conditioning. For the winner of the Ironman along with all of the other competitors that finish within the requirements of the race, they can exclaim what is also the registered trademark for the competition: Swim 2.4 miles! Bike 112 miles! Run 26.2 miles! Brag for the rest of your life.

See also Bicycling ; Running ; Swimming .



Huddle, Paul, and Roch Frey. Triathlon: Starting Out: -Training for Your First Competition, 3rd ed. Aachen: Meyer & Meyer Sport, 2017.

Katch, Victor L., William D. McArdle, and Frank I. Katch. Essentials of Exercise Physiology, 5th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins Health, 2016.

Kleanthous, Mark. The Complete Book of Triathlon, 3rd ed. Aachen: Meyer & Meyer Sport, 2016.

Müller, Mathias, and Timothy Carlson. 17 Hours to Glory: Extraordinary Stories from the Heart of Triathlon. Boulder: Velo Press, 2010.

Mora, John. Triathlon 101. Champaign: Human Kinetics, 2009.

Roberts, Oliver. The Complete Triathlon Triathlete's Training Manual. Hauppage: Barron's Educational Series, 2010.

Trew, Steve. Be Your Best at Triathlon, 2nd ed. Blacklick: McGraw-Hill, 2010.


Ironman. (accessed January 18, 2017).

Rose, David. “Ironman Athletes Put Hearts at Risk of Fatal Damage, Experts Warn.” The Times Europe (January 22, 2007). (accessed January 18, 2017).

Wagner, Karl-Heinz, et al. “Ironman” Risk Assessment of IRONMAN Triathlon Participants. Oxidative Stress and DNA Stability, University of Vienna. December 2008. (accessed January 18, 2017).

Whitney, Blake. “Ironman's First Champ, Gordon Haller, Looks Back 25 Years.” . October 20, 2003. (accessed January 18, 2017).

Winkler, Sarah. “What is the History of Triathlons?” . July 14, 2010. (accessed January 18, 2017).


International Triathlon Union, 998 Harbourside Dr., No. 221, North Vancouver, V7P 3T2, Canada, 1(604) 904-9248, Fax: 1 (604) 608-3195,, .

Ironman, 2701 N Rocky Point Dr., Ste. 1250, Tampa, FL, 33607, (813) 863-5940, Fax: (813) 863-5930, athlete, .

William A. Atkins, BB, BA, MBA

  This information is not a tool for self-diagnosis or a substitute for professional care.