What is the difference between an IRONMAN 70.3 and a full IRONMAN?

Both combine swimming, cycling and running into one of sport's toughest endurance challenges, attracting Olympians, world champions and thousands of amateur athletes each year.

The key difference, however, is simple: an IRONMAN 70.3 is exactly half the distance of a full IRONMAN.

Here's everything you need to know.

What is an IRONMAN 70.3?

An IRONMAN 70.3 consists of three disciplines completed consecutively:

• 1.9km (1.2-mile) swim
• 90km (56-mile) bike
• 21.1km (13.1-mile) run (half marathon)

Together, those distances add up to 70.3 miles, giving the event its name.

Although it is considered the shorter version of the sport's flagship race, there is nothing easy about an IRONMAN 70.3. Elite professionals often finish in under four hours, while many age-group athletes spend six hours or more completing the course.

What is a full IRONMAN?

A full IRONMAN doubles each discipline:

• 3.8km (2.4-mile) swim
• 180km (112-mile) bike
• 42.2km (26.2-mile) run (marathon)

Those distances total 140.6 miles, making it one of the most demanding single-day endurance events in the world.

Completing a full IRONMAN requires months of preparation, with professionals racing for more than seven hours and many amateur competitors taking anywhere between 10 and 17 hours to reach the finish line.

IRONMAN 70.3 vs IRONMAN: What's the difference?

Which race is harder?

Both races demand exceptional endurance, but a full IRONMAN is widely regarded as one of the toughest events in world sport.

Doubling the distance means athletes must manage their pacing, nutrition and energy levels over an entire day of racing, with the marathon often becoming the decisive challenge after hours already spent swimming and cycling.

That said, an IRONMAN 70.3 remains an elite endurance test in its own right. The shorter distance encourages a faster pace from start to finish, leaving little room for error.

Which should beginners choose?

For athletes moving into long-distance triathlon for the first time, an IRONMAN 70.3 is often the natural starting point.

The reduced distance requires less training and recovery than a full IRONMAN, while still providing the experience of completing one of endurance sport's most iconic formats.

Many professional triathletes also compete extensively over the 70.3 distance, meaning newcomers have the opportunity to race on the same courses as some of the world's best athletes.

How does the IRONMAN Pro Series work?

Both full-distance IRONMAN races and IRONMAN 70.3 events form part of the Experience Oman IRONMAN Pro Series.

Throughout the season, professional athletes earn points based on their performances across selected races, with the highest-scoring competitors crowned Pro Series champions at the end of the year.

That means victories at events such as IRONMAN Hamburg, IRONMAN Lake Placid and IRONMAN 70.3 Swansea all play an important role in deciding the overall title race.

How to watch the IRONMAN Pro Series on DAZN

Fans can watch the Experience Oman IRONMAN Pro Series live on DAZN throughout the season.

Coverage is available in all territories except Canada, the United States, Central America, Anguilla, Antigua and Barbuda, Aruba, Bahamas, Barbados, Belize, Bermuda, Bonaire, the British Virgin Islands, Cayman Islands, Cuba, Curaçao, Dominica, Dominican Republic, Grenada, Guadeloupe, Guyana, Haiti, Jamaica, Martinique, Mexico, Montserrat, Puerto Rico, Saint Barthélemy, Saint Kitts and Nevis, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Maarten, Suriname, Trinidad and Tobago, Turks and Caicos Islands and the US Virgin Islands.

To watch:

• Download the DAZN app on your preferred device or visit DAZN.com.
• Sign in or create a DAZN account.
• Search for the IRONMAN Pro Series.
• Select the live event and start streaming. 

IRONMAN 70.3 and full-distance IRONMAN races both test endurance, but what separates them? Here's everything you need to know.