What you need to know about running your first triathlon

Whether you are looking for your next competitive challenge, seeking to raise money for charity by pushing yourself a little further or just looking for a bit of variety from your sport, triathlons are definitely worth a look, so here’s the beginner’s guide to your first triathlon

Triathlons are fun friendly events which let people from different backgrounds compete on a level playing field whilst offering a much broader fitness base than any one single event can deliver.

From small try-a-tri and relay events up to the extremes of a full Ironman, there are events for everyone, and, if you don’t fancy the swim, you can always try your hand at the Duathlon.


If you want to dig a little deeper, you can find everything you need to know about starting out in triathlon in these pages or in the more comprehensive videos and online courses. From choosing your first triathlon to training and equipment and getting through the day itself, your first triathlon is an experience you will never forget!

What’s a triathlon anyway?

Triathlon is one of a range of sports that fall under the umbrella of Multisport and have become very popular over the last 10 years or so, principally because they appeal to a wider range of athletes from different backgrounds letting each compete based on their own strengths and experiences.

Whilst the lengths may vary, all triathlons involve 4 key disciplines and its the interplay between the 4 that are at the root of triathlon’s appeal and its challenges, coupled with the need to train for and master very different sports and their associated equipment.

The races invariably start with a Swim, which is generally the shortest event by time and distance, followed by a Cycle and concluding with a run. Between the three events, you move into transition as you change from wetsuit to cycling shoes and gear before you jump off your bike, put on your trainers and head out on the final run.

Where the fun begins is the fact that you use radically different muscles, in different environments and this leads to some funny physiological demands as you move from event to event, but more on that later!

Why do your first triathlon

If you haven’t taken the leap to sign up for your first triathlon, the sport has a huge amount going for it.

For one, it’s one of the friendliest sports I have taken part in, partly driven by the fact that you spend a LOT of time waiting around before races as they set up their transition pitch and are always happy to chat to whoever’s next to them! But also because we all recognise that it’s a tough sport so feel that anyone that’s willing to put the time and effort it deserves our respect and encouragement.

Secondly, it’s flexible. I came from a running background and started to cycle as a cross-training activity to alleviate overtraining injuries I was suffering. Unlike a marathon or century race, you are training 3 distinct muscle groups which reduce your training load and gives you the chance to continue to train even if you have picked up an injury in one are.

This leads to another advantage which is time. Very few of the training sessions are more than an hour and can be less. An average swim session for a Sprint triathlon will probably be less than 30 minutes, so you get the chance to fit your training sessions around your life more than you can with some sports. You can easily complete the cycle leg based solely on cycling to work for example.

Finally, you are not competing with everyone. I firmly believe the only person you need to compete with is your self and what other people do isn’t relevant, and Triathlon gives you the opportunity to do that. Firstly, you compete in age groups, so you’re not racing against the 18-year-old next to you, but other people of similar age profiles and experiences which gives you a realistic expectation of what your level really is. Secondly, triathlons are all different, so there is no real concept of a personal best, only a PB on that day in that race. A lake swim on a calm summers day is a completely different experience to a later September sea swim with an offshore breeze for example, and the cycles can range from flat to mountainous which massively impacts on your time both for the cycle and the run that follows.

Know why you are doing a triathlon

Like most endurance sports, Triathlons have a huge mental component and when your half way through and wondering why you’re doing this, it’s nice to have an answer!! More to the point, your reasons for choosing a race will have a major bearing on your satisfaction. If you’re looking for a challenge, there’s little point in picking a try-a-tri race, as it may not leave you fulfilled.

If you’re just looking to take part and see what it’s all about, many of the larger races will run try trim races with much shorter distances that let you dip your toe in without stretching your self. And if’ its a group thing, then there are a number of relay options which let teams of 2 or three split the event with one doing the swim and handing over to a cyclist and then a runner.

These are often good team building events as well. Each year, several hundred Vodafone employees take part in the Dublin City triathlon relay as part of a wider corporate wellbeing initiative, and it creates a great atmosphere.

Obviously, if you’re looking for more of a challenge, you can go long, and aim for a full or half ironman, or pick a challenging terrain, with sea swims like the Alcatraz race or the range of mountain triathlons offering a much more challenging experience.


best irish Triathlons
best irish Triathlons

Practical considerations for triathlon

Any attempt at a triathlon needs to be taken seriously so there are a few practical considerations to consider

How much time until the race

Depending on your existing level of fitness, most triathlon training plans will run from 12 to 16 weeks, so this needs to be taken into account


Remember that you need to get to the event with a bike, wetsuit and a whole host of other kit and probably 90 minutes before the race. How are you going to get there? how much time do you need? Do you need to stay over?


You can’t do a triathlon in isolation, so you need to factor in your other work and family commitments into your schedule. Depending on the race, this could be anything from 6-20 hours per week just for training.


Triathlon is not a cheap sport. The races are getting more expensive as they are logistically challenging and need signification support from the sanctioning body, plus you are likely to need to pay for a race licence, travel and obviously have access to a wetsuit and bike at the very least. And don’t forget the cost of training in the local pool.


Why are there different race distances?

The more time you spend with triathletes you come to realise that there are two similar but different groups that organise events, one coming from the shorter distances and the other from the longer distances and this has led to the development of two different definitions of the race distance. Understanding the history of triathlon will help you understand were these difference come from.

Triathlons, as managed by the ITU, sprang from the San Diego Track Club in the early ’70s, where a  multisport event was devised as an alternative to constant track running. This started with a 10k Run, followed by an 8k run and finishing with a 500m swim. Since the winning Olympic status in 1989, this was standardised to the format we know today with a standard Olympic distance race being a 1.5km swim, a 40km Ride and a 10k run, although the majority of races are run over the shorter sprint distance.

At the other extreme is the Ironman race, which is now run by the WTC under the IRONMAN brand ( although other organisers use the same distances under different names like the Challenge series or the famous Norseman event). This developed as a challenge between extreme athletes in Hawaii who wanted to prove that their sport was the toughest and its competitors were the fittest, so they developed a race on Kailua-Kona Island which combined 3 existing extreme events, a 3.9k swim, a 185km cycle and culminating with the Honolulu Marathon.

The Kona Ironman has legendary status amongst long-distance triathletes and completing a full Ironman is still at the top of most Triathletes bucket lists!

However, you don’t need to go to those extremes to enjoy the sport and the vast majority of people who regularly compete in triathlons are more than happy to stick to the standard distances

Triathlon variations and distances

Some people will already have picked their first race because at charity or work event, but if not, the choice of triathlon variations, distance and race terrain can have a major impact on your enjoyment and how you proceed into the future.

Depending on where you live, you’re likely to have a lot of options, so let’s consider some of the options and the factors which may impact on the best race for you.

Triathlon variations

If you’re looking to get into multisport but have difficulties with one of the events, then there are a range of other options available.


The simple swim/cycle/run format is the most common race and you’ll find a large number of events with differing swims, terrains and distances to choose from


If like many people, you’re put off by the idea of the swim, then duathlon may be the event for you, and many countries will have national duathlon series which are every bit as competitive and the mainstream duathlon series. Duathlons will have three legs in a run-cycle-run format, so the transitions still exist, but you cont need to brave the water or invest in wet suits to compete.


For the non-bikers, aquathlon ( or Aquathon) could be the sport of choice with their run-swim-run format. These are less common but you will find many clubs running these events as part of their training cycle in the run-up to the main season, as a way fo getting people into open water early in the season. You will also find Swim-Run versions which tend to have a longer run leg that the three-part options. These events lend themselves well to adventure and extreme variants, including island hoping events over many legs and approaching ironman levels of endurance.


Rounding out the options are the aqua bike events, which are particularly good for people who’re protecting knees or for whom running is best avoided. These are relatively new triathlon variations and there is some variability in the types of event that are run. Because of the need to change into wetsuits, they tend to be two leg events though and will have a standard length swim and a longer cycle, e.g 750m swim and 4km cycle.

Triathlon Distances

Depending on who’s running the Triathlon there are a couple of different race distances.

ITU events are based on the Olympic standard distance with the shorter and longer version being multiples of the standard Triathlon distance. The 3 main variants are:

  • Sprint race – 750m swim, 20k cycle 5k run
  • Olympic – 1500m swim, 40k cycle, 10k run
  • Long/Double Olympic – 3km Swim, 80km Cycle, 20k run

Ironman events have the same format but are fractions of the original Kona triathlon distance so tend to have a longer cycle and run legs. These three versions are:

  • 51.50 – a relatively new race designed to compete with the Olympic format with the same distances 1.5km swim, 40km cycle, and a 10km run.
  • Half Ironman or 70.3, which may be called a middle distance triathlon for non-ironman brand events. This is a 1.9km swim, a 90km cycle and a half marathon ( 21.1km)
  • Full Ironman ( long-distance triathlon) – the original ironman distance with a 3.8km swim, 180km cycle and a full marathon ( 42.2km)

There are longer triathlon distances or combined races that appeal to the extreme athlete, plus variations to account for logistical and geographical peculiarities.

Where does the triathlon swim take place?

In the swim, there are two broad categories, indoor and open water.

Triathlon Swim
triathlon Swim

Indoor pool triathlons are becoming less common, partly because they limit the number of entrants, are more difficult to organise as they require a large pool with space outside for transition and tend to be very warm, which places extra strains on the athletes due to the heat and the fact you are no longer wearing a wetsuit.

Open water swims are the norm for most races as they are plentiful and generally free to run! Unless the water is very warm, a wet suit is required however and they bring other environmental challenges, like visibility, current, tide, wind, animals, vegetation, temperature and a host of others.

Sea swims tend to be colder, affected by the tides and winds and require you to contend with the salt especially around the neck of your wetsuit.

River swims generally have an upstream and downstream section so need to be paced accordingly, but there is nothing better than surfing the flow on the downstream leg, however!! Like lakes, there is likely to be vegetation, and the depth will be dependent on the weather.

Lakes tend to have static water and can be deep, which makes them ideal if you’re a little uncertain. The lack of flow can make them cold, however, especially some of the deeper mountain lakes favoured by ironman events in Europe. But at least you know the water is fresh, clean and pure!

Finally, there are canal swims that are straight, have no current, and if active, tend to be kept clear of debris and vegetation.

Bike and run terrain

No matter what event you are signing up for, make sure you know the terrain and prepare accordingly. There is nothing worse than finding you’ve got a 500m climb halfway through an event that you’re not prepared for, but the grades and shape of the event can have as much of an effect for the unprepared.

positive mental skills triathlon
learn the mental strengh needed to triathlon




The race website will probably have a map of both courses, and most will have a link to a mapping or training site like Strava, Komoot, or Ride with GPS, but if not, you should be able to easily copy the race map into one of these sites to get a clear sense of the type of terrain you are going over.


Traditional triathlons tended to be relatively flat, and tribes are designed with consistent speed in mind. In these events, speed and endurance will be the focus and will favour the more aerodynamic bikes and riders ( more on this later). Be aware of the likely winds though as a strong, consistent headwind can be more energy-sapping than a range of mountains whereas side winds will impact bike handling. Increased power on the bike is likely to come from increased cadence rather than power.


Rolling hills will require a more sustained effort at mid-range power outputs as longer hills with gradients in the 3-7% range will be the norm. Power endurance will be the key determinant of performance, and the weight of the bike and rider will begin to affect performance more than aerodynamic efficiency.


The technique will become key in this area, both up and downhill. The key difference will be gradient and the ability to grind gears ( lower cadence but more power per stroke) and sustain high anaerobic effort will be required. You are likely to achieve a higher peak heart rate during these steep climbs as well. On the downhill sections, your courage and ability to tactically utilize your brakes and take sharp bends at speed will determine average speed.

Mountain courses tend to be more common in Ironman events than shorter races, however.

Technical city courses

In cities, triathlons tend to incorporate short stretches of good pavement and lower average gradients. However, the turns will mostly be right angles and will bunch up the field, especially during the run.

Cross country triathlon variations are also becoming more popular especially with the mountain bike crew but these tend to be a more specialised event.

Main Governing Bodies and Organisers

Triathlon is governed globally by the ITU, who are responsible for the amateur sport through a range of regional and national bodies. These bodies are charged with developing the sport locally both at the participant and competitive level and will have the mandate to develop the sport locally. Most will manage the licensing of athletes, the sanctioning and marshalling of races and the promotion of events. Athlete development programmes and nationally support competitors will also fall under the remit of these bodies.

Unlike some sports, the national Body is generally there to support anyone who wants to take part in the sport, from the first-timer doing a charity event through to elite competitors and will provide training and support for anyone that needs it so should be supported by anyone taking part.

They should also be your first port of call if you are looking for information and many will provide guidance, support and potentially training plans for those wishing to compete. It’s definitely worth looking to see who your national triathlon body is.

Commercial events, such as Ironman, don’t fall under the remit fo the governing bodies but are also driven by the desire to see more people participate and enjoy the support so are worth investigating if you want more information, especially on the longer events. Much of their content is revenue generating, however.

The main international regional and national bodies are linked below, and if your country is not listed, look at the site for your region and you should find a national link there.


African Triathlon Union 

American Triathlon Confederation 

Asian Triathlon Confederation

European Triathlon Union 

Oceania Triathlon Union 







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