How long is a Half or Middle Ironman triathlon?

So, you’ve read up on and maybe even taken part in a triathlon or two, but did you know that there are actually 5 different race distances that are recognised in the world of triathlons?

How long is a half ironman

The different race lengths range from the super sprint, which is the shortest at just under 14km, to the full Ironman at just over 226km! As you may have guessed from the title a Half, or Middle, Ironman comes in at half of the total distance of a full Ironman

Triathlon races are divided into age groups. This means that you will be competing alongside other triathletes who fall into the same band for age and sex as you, with the exception of triathletes who fall into the separate elite category.

If you’ve completed an Olympic triathlon already and are thinking of taking the next steps to complete an Ironman, a Half Ironman is the perfect in between challenge to help keep you focused on increasing your fitness levels and training intensity.

How far do you need to swim, cycle and run in a Half Ironman triathlon?

If you’ve been looking at triathlon events to join, you’ll have seen some Ironman or Half Ironman events popping up.

A Half Ironman still follows the same structure as any other triathlon distance; swim start, cycle and running to the finish line. A longer distance again than the Olympic distance, serious training hours are needed to prepare for a Half Ironman. The total distance for a Half (or middle) Ironman is 70.3miles, which is broken down as:

Swimming – 1.9km (1.2 miles)

Cycling – 90km (56 miles)

Running – 21.1km (13.1 miles)


If you’re looking to work your way up to a Half Ironman, we would suggest first trying out a sprint or Olympic distance race.


A triathlon is one of the trickiest and most difficult types of event you can try, but the challenge is what makes it great. It comprises of a swimming section, followed by a large bicycle ride, and finally a long stretch of running.

For anyone who has ever done an event involving one sport, such as a 10K run, and found themselves bored by the end, a triathlon might be the exciting fitness challenge you’ve been looking for! Combining three sports – swimming, cycling and running, a triathlon provides a varied and challenging workout that test your fitness and endurance across multiple disciplines.


Find a Traithlon near you


Sprint | Super Sprint | Olympic | Half Ironman | Ironman


What is a triathlon made up of?

The distance of a triathlon can vary, but the race will always begin with a swim start. Depending on the length of the course this could be in a swimming pool or an open water swim such as a lake or sea. 

The swimming section of the triathlon is then followed by a cycling section – beginners don’t need to splash out on an expensive new bike, if you already own a mountain bike you can use that for your first few races! The cycling section is considered by many triathletes to be the most challenging part of the endurance event, with standard triathlon courses incorporating a 40km bike leg.

The final leg of the triathlon is a run. Again, the distance will vary depending on the length of the course, but a 10k run is considered standard for a triathlon. 

Between stages there is also a transition, which is often referred to as the fourth discipline. The transition area is where you change your kit between stages, for example switching from your cycling gear to your running shoes. The time it takes you to do this is counted as part of your total triathlon time, so serious triathletes will have got their transitions down to a fine art.

What are the benefits of taking part in a triathlon?

Triathlons are great for those who are looking to improve their fitness, lose weight but don’t like the idea of doing a regular marathon of running event. The varied stages keep training and competing challenging and interesting, providing a total body workout. Those prone to running injuries may also benefit from the swimming and cycling sections, as the movements are lower impact on joints.

Regardless of sprint length, triathlons are typically divided into age groups. This means that you will be competing alongside other triathletes who fall into the same band for age and sex as you, with the exception of triathletes who fall into the separate elite category.

Top Triathlon Events in 2020

We have picked out the best events taking place in 2019. We have lots more listings available, just click on the 'Triathlons' tab at the top of this page to find them.

Ironman UK Wales

This event is well established as having one of the most challenging bike and run courses on the IRONMAN calendar.  It also boasts the most spectacular swim location of any IRONMAN event, and the inspiration gained from one of the most vocal and enthusiastically-supported events with tens of thousands of spectators who turn out for race day on all three disciplines.

Find out more about the Ironman Wales event here

Ironman Wales - Triathlon Event