Whether you have entered, or are considering an IRONMAN, you may be wondering how on earth you train for an IRONMAN. The scale of the challenge feels so overwhelming that it’s impossible to know where to start. In this article I’m going to break it down discipline by discipline, then pull it all together at the end.
How to train for the IRONMAN swim
For most, the swim is the most intimidating part of triathlon. By the time we’re looking at swimming 3.9KM (2.4 miles) in open water, this strikes fear into the heart of many. So much so, that it may put them off of the event altogether.
The first thing you need to work on is your technique. Without good technique, you will waste enormous amounts of effort while going absolutely nowhere. I highly recommend you hire an in person coach to help you with your swimming. If you are very new, then a 1to1 lesson would be far more useful than attending a group or club session. This will have the full attention of a coach, whose attention is split in a group session..
You will also want to find a coach who specialises in triathlon. Helping someone prepare for swimming such a long distance in open water is very different to coaching someone for a 100M sprint.
If you don’t live near a triathlon coach, or can’t afford a full coached session, you may want to consider my online swim stroke analysis. However, you will need to be able to swim a length of freestyle (front crawl) for me to be able to give any meaningful feedback.
Top tips for triathlon freestyle
- Exhale when your face is in the water, so you don’t have to inhale and exhale when your fae is out of the water
- Imagine there is a black dot on the palm of your hand that you want to show to the wall behind you as you swim
- Keep your elbow above your wrist, and your wrist above your fingertips at all times
- Look down at the bottom of the pool, but ever so slightly forward, rather than bolt down with your chin touching your chest. This puts you in a more natural position for breathing, and gives you a greater appreciation of what’s going on around you in open water.
- Save your energy for pushing the water behind you, rather than on slapping the water. This may feel good, but doesn’t actually generate any propulsion.
Once you have improved your technique to a point you can swim 100M continuously without exhaustion, we probably need to switch the focus to building distance. While every triathlete should continue refining their technique no matter how long they’ve been in the sport, if we have to swim 3800M we need to put in the hard yards.
This isn’t just a case of swimming continuous lengths (although there is a place for that). It’s about including intervals, sprints, drills and more.
Once you are confident swimming for several hundreds meters and the weather allows, it’s time to get in the water. This is very different to pool swimming, so you’ll need to get plenty of practice in ahead of race day.
Open water swimming
I highly recommend you get a wetsuit before you start open water swimming. That is unless you live in a very warm part of the world. The extra insulation and buoyancy that comes with a wetsuit will make an enormous difference. You can find tips to help you pick out a wetsuit here.
Wetsuits will let water in (they’re not drysuits), but that layer of water will warm up to body temperature. Keeping you protected from the cold.
In the open water you will not be able to see the bottom. You will need to practice lifting your head (or ideally just your eyes) out of the water to see what’s ahead. This prevents you swimming off course and adding unnecessary distance to your swim.
You will also need to contend with waves, windy conditions, other swimmers in close proximity and swimming round buoys. There is a lot to contend with, so you NEED to get plenty of practice in ahead of race day.
You will want to build up distance in the open water, and get to the point where you can swim the full distance in training.
How to train for the IRONMAN bike
The swim is intimidating and complex, but the bike is what takes up most of the day. If you are new to triathlon, the bike is going to be very different to your previous experience of riding bikes.
For a start, you will be pedalling (almost) completely nonstop for 112 miles. You need to develop legs and lungs that will be able to cope with these demands. In a triathlon you can’t surge hard for a time and then coast to let your legs recover. It’s not as simple as smashing it up a hill then sit at the top getting your breath back.
We’re going to be out on the bike for a long time, so we need to ride at a slow, consistent pace. At an intensity where we could hold a conversation with someone riding alongside us. This is quite boring, especially for those who have come from team sports, or racing shorter distances. But it’s the only way we can ride for 180KM without exhaustion.
Most of our training is what’s known as polarised. Where our training is either of a low intensity, or a very high intensity. If you ask most people to go out and train for cycling, they will ride at an intensity which is mildly uncomfortable for around 30-40 minutes and call it a good workout. We need a much more thoughtful and focused approach to train for something like an IRONMAN.
Indoor training
If we’re trying to train in a focused manner, then riding outside can make that difficult. You may be very lucky and live somewhere with plenty of long, flat roads where you can ride at the intensities required to hit the right energy systems, without needing to worry about hills, potholes or the weather.
This is where indoor training comes into its own. This involves attaching our bike to a trainer which allows us to ride out bike indoors, with the trainer which can can change resistance for us. This is usually paired with an indoor training platform such as Zwift, Rouvy or TrainingPeaks Virtual which allows us to ride around a virtual world or follow a workout, with the trainer changing resistance for us at points such as on hills.
We can also take part in races on these platforms, allowing us to test ourselves against other riders around the world, and add a competitive aspect to our training in a controlled environment.
While it would be a stretch to claim that you need an indoor trainer to compete in IRONMAN, I would say somewhere around 95% of competitors will, and the 5% who choose not to will be those at the highest risk of failing to finish.
Cycling power
When we are training with purpose, we need targets to train towards. Just heading out for a ride won’t cut it.
Most new cyclists would gauge their progress on the speed they’re riding at. If they averaged 12mph on their ride last week and are closed to 13mph this week, they see that as being improved fitness. Which it may well be,
However, it could also be differences in the wind, air pressure, the amount of hills, road surface, or tyre pressure. There are far too many variables for speed along to tell us the whole story.
In the 80s we started tracking heart rate to inform us of how hard we were working during a session. This was a breakthrough It could help us ensure we were targeting the right energy systems by using fitness tests to identify different training zones.
This wasn’t a perfect system however. It necessitated the use of a chest strap, which sits close to the heart and measures how fast the heart beats. There is only so accurate this can be if the strap slips, the battery is low, or can’t find a good connection for any reason. Heart rate also takes a long time, up to 30 seconds to respond to an effort. You could end up 30 seconds into an interval before you know whether you’re hitting the right intensity.
This is where cycling power comes in.
This is a measurement that is taken from an indoor trainer, or a power meter mounted onto your bike. It measures both the torque (force applied in a rotational plane), and how fast you are pedalling (your cadence). This gives you a number in watts which represents how hard you are working at any given moment in time. This refreshes every second, giving instant, accurate data.
Most cyclists will measure their bike fitness with functional threshold power, or FTP. This involves taking a fitness test at max effort which will give us a number representative of our current fitness. If you record an FTP of 120W then after three months of training see an increase to 135W, this is an indication you are getting faster.
While cycling power is not required to train for an IRONMAN, it is highly recommended.
How to train for the IRONMAN marathon
he idea of running a marathon after swimming 3.8KM and riding 180Km is enough to make most people’s heads spin. So how do you train for this feat of endurance?
The first thing to point out is that your performance over the marathon is intrinsically linked to your bike performance. If your bike fitness is poor then you will be starting the marathon exhausted. While you’ll never be starting it fresh, there’s a big difference between heading out onto the run with wooden legs, and lying on the floor of T2 in tears because you can’t face what’s ahead (yes, this happens).
Assuming your bike fitness is up to scratch, how can we prepare for the best run possible?
The simple answer is lots of running at a slow pace. If we can run for 3-4 hours a week in training, this trains us to be able to grind out a marathon on tired legs.
We definitely need some long runs, but this is the number one trap that athletes fall into. Believing that they need to run a marathon before their IRONMAN. This is a massive mistake, unless they are already a seasoned marathon runner.
Why is it such a mistake? Because of the time required by the marathon training, the fatigue it creates and the injury risk. Marathon training usually requires 3-4 runs a week minimum, including a fatigue inducing long run.
Most IRONMAN athletes aiming for a marathon will choose to run a spring marathon. This means long runs through winter, when athletes are less fit. This level us less time for cycling and less time for strength training.
We can of course do a spring marathon if our performance over the IRONMAN isn’t all that important to us. We can drop the run volume massively after the marathon and go heavy on the cycling, but this isn’t ideal, as our run fitness will be lacking on the big day.
So if we’re not doing a marathon in training, what should our prep look like?
Training for durability
The biggest indicator of run performance is volume rather than intensity, especially over these distances. I would much rather someone runs for four hours easy a week, than two hours at higher intensities. The second athlete will crumble on race day.
When I did my first IRONMAN I could run 5K in under 18 minutes. That didn’t stop me taking over five and a half hours to complete the marathon though. Speed I had in spades, but the run of your first IRONMAN isn’t about speed, it’s a war of attrition.
This isn’t to say we ignore intervals entirely, but they’re definitely a lower priority than they are over other distances. As with cycling, we want to spend most of our time in zone 2. As frustrating as this pace may be to run at in training, if you were able to hold it over the entire 42.2KM after completing the bike and swim, you’d probably be happy with that.
My job as a coach is not to turn would be IRONMAN finishers into classic, rake thin marathoners. It’s to create runners who keep relentlessly moving forward for hours. Thos who will end up passing everyone around them who is forced to a walk.
During your first IRONMAN there is a very high chance you will need to slow to a walk. I have coached a handful of athletes who have managed to run every step of their first IRONMAN marathon. But most will slow to a walk for the aid stations if nothing else.
Pulling it all together
As well as these components, we need to consider strength training, nutrition, race day logistics, diet and a huge amount of other factors. IRONMAN really is a lifestyle, and you could spend hours a week doing research.
The best place to start is with a training plan. If you want a high quality plan written by a human that comes with a selection of free materials to support you in your training, check out my training guides here.
