How to Train for an Ironman - Part 2 - Swimming

author : Tre_bor
comments : 8

In this month's article I will talk about swim frequency, pacing, technique, goggles, wetsuits, sighting, mass practice and open water training.

In the first article of this mini series on "How to Train for Ironman" I covered some basics about preparation and hopefully provided you with some information that got you thinking more about what Ironman training is like. Did you answer the questions?

In this month's article I would like to look specifically at the swimming section of an Ironman race.

Discipline: Swimming

Distance: 2.4 miles - 3.8 kilometers

Avg. Time: 1 hour 15 minutes

% of Total Race Time: 10%


The swim section of an Ironman race is 2.4 miles or 3.8 kilometers. It might not be the longest of the three disciplines but with up to 2,000 people trying to swim in the same place at the same time, some might see it as the toughest. It can get very crowded and quite rough which may make you panic, even if you are an experienced swimmer. However, with a little practice I assure you that you will be fine.

For most people the swim section of the race is their weakest. It's quite common for people to cycle and run but swimming is just not as natural or as common for people to practice as a sport. Especially here in the UK where open water spots or the sea are rarely warm enough to take a dip without a wetsuit and a hot shower immediately afterwards.

Let's get straight into some key points that I would highlight for first time triathletes, especially if you are going to be taking on an Ironman.

1. Little and Often

Swimming is all about having a good feel for the water. You need to swim regularly to maintain and enhance this level of feeling. Without it you will be swimming inefficiently and probably look like you are fighting against the water.

If you are time crunched, as an example, swimming three times a week for 30 minutes at a time is better than swimming once a week for 90 minutes. Littler and often is the key to improving your swim so try to fit your swim sessions in on your lunchtime work breaks.

2. Pacing

Getting a fast time in the swim really isn't a good idea unless you know what you are doing. Let's imagine that you are aiming to go 10% faster than normal in the swim section and your predicted swim time was going to be 1:20. That's a savings of eight minutes. But to get that extra 10% probably requires 20% more effort. It's much better to save your energy for the bike or run sections for two reasons: 

  1. You are just at the start of a very long day so you will need to reserve your energy for later
  2. Putting more training effort in on the bike or run disciplines will save you more time in comparison to the swim

There is a saying that one of the special forces use: "Slow is smooth, smooth is fast". I love that saying and it couldn't be more relevant than in swimming. When trying to swim faster you are probably wasting a whole load of energy unless your technique is super refined. It's better to be smoother and "slower" because you will glide more effortlessly through the water and you will probably find that you are faster by doing that, not to mention that you will use far less energy. 

Quick Tip:

 Whenever you get in the water do an exercise called "sink-downs". This involves exhaling fully underwater and then coming back to the surface. In a pool you should sink to the bottom, hence the name. Doing this will help you feel more comfortable in the water, relaxing your muscles and hopefully helping you find your rhythm quicker in open water. This is especially useful in colder open water events where you will find it hard to catch your breath.

3. Technique

Being efficient in the water cannot be stressed enough. You cannot brute force your way through the water so working on technique is absolutely critical. In fact, I'd say that you can let your running and cycling take care of your cardiovascular fitness and concentrate mainly on technique in the pool. 

I learned a little too late that I had bad technique which meant I had to take what felt like a step backwards in order to progress. I had to re-learn the correct technique because I had picked up some really bad habits. This is where I would highly recommend heading to a dedicated swim trainer who uses an Endless Pool with video cameras to film you in action. It's amazing how you look compared to how you think you look. You are probably doing movements which you know are wrong but just don't realise you are doing them. Video analysis will help you immeasurably.

Body position is so important in the water. No matter how hard you can push back the water with your hands if you have low lying legs in the water you are going nowhere fast! The biggest pointer I can give you it is to stretch out your lead arm as far as possible when in the water. There are many reasons for this but the most important one is that by doing this you will keep your weight distributed more evenly in the water, and hence have a flatter and therefore more streamlined body position. By not stretching your arm out the weight is distributed more towards your legs and will make your legs sink down, leading to a really inefficient body position and a large amount of drag in the water. Think of it like a see-saw with your hands at one end and feet at the other.

4. Goggle Wearing

How do you wear your swim cap and goggles? A lot of people wear one cap, then put their goggles on and then put the race swim cap over the top. This helps to keep their goggles in place and not get ripped off by someone accidentally. There really is no right or wrong way to wear them but you do need to be consistent. It's no good trying something on race day that you have never done in training before because the person next to you says it's better.

A friend of mine had his swim goggles break after only 300m of his first Ironman race...He didn't have a spare pair so had to try and complete the remainder of the 3.8km swim without any. Needless to say he didn't! You can leave a spare pair or old pair on the bank if your swim incorporates a two lap course. Most of the time they do and there is a place for people to leave glasses/contact lenses and asthma inhalers, etc. For all that hard work to be ruined within a few minutes of the start would be a waste. 

5. Wetsuit Swimming

Swimming in a wetsuit is very different to swimming without one. Your legs are more buoyant and therefore your body position is usually very different. Your arms are more restricted and this may cause your muscles to fatigue in different areas more quickly so get out there as much as possible and practice. If your legs usually lie low in the water then you are going to get an advantage by swimming in a wetsuit.

Very importantly, find out if the race that you are entering has ever had a wetsuit ban in previous years. If it's possible that you are going to have a non wetsuit race because the water temperature is too warm you need to make sure you have trained without a wetsuit for the full distance swim in open water.

6. Sighting

You're probably sick of hearing it by now but you must be able to sight. Just practicing in a swimming pool isn't any good either because the pool is so different from open water. You need to learn how to sight reliably in open water in all kinds of conditions, such as with the sun in your eyes or when there is a lot of chop from people around you. The only way to get better at this is to get outside in open water and perfect your technique. Your time and arms will thank you for swimming straight...

When I took part in my first triathlon I was swimming breast stroke with my head out of the water. This meant that I could see exactly what was going on around me, and how far off course people were swimming. It was unbelievable! I'm not exaggerating when I tell you that people were swimming off at 45 degree angles, head down and no sighting. They probably swam 20% further than if they had swum straight. That was a valuable lesson for me.

7. Mass Practice & Open Water

You must practice in a large enough group to simulate race conditions. If you don't, and have no experience of swimming in groups, you are going to panic and not feel comfortable. If you can't practice in a large group make sure that you enter enough races before the main event to give yourself exposure to group starts and swimming with others.

In addition, try to swim in lots of different types of environment. Lakes, rivers, reservoirs, the sea, etc. Some are really clean, others are dirty and you can't see a thing and some have lots of weeds which can cause a bit of panic. If you have trained in all kinds of conditions and environments, come race day nothing will give you any cause for concern.

That concludes this article on Ironman swim advice. In the next article I will be discussing bike specific advice for the beginner Ironman triathlete. If you have any questions, no matter how silly you may think they are, please do ask them in the comments section below. I know what it's like to have a fear of the water and overcome it so I'd love to help others do the same.

Author Bio: Robert Jackson this year became an Ironman! He believes a balanced, yet consistent, approach to training and diet will deliver results. Having started out with a fear of the water, he managed to complete the 3.8km Ironman swim in 1.5 hours just 11 months later, proving that "anything is possible...". Robert has recently created a website to guide those looking for protein powder. Click here to find out more.


Click on star to vote
41332 Total Views  |  101 Views last 30 days  |  27 Views last 7 days
date: February 7, 2014


I have just started to train clients in Canary Wharf, London. See my website for more details.