How to pace an Ironman

Just how important is it to pace an Ironman effectively and how do we go about it?

An Iron distance race is like very few other triathlons, in that you need to get so much right (and have a little bit of luck) in order to execute your race strategy. Training, nutrition and even clothing are areas that you'll have been working on during the months that you've been training and building towards race day and you should be approaching your race with confidence and positivity in the knowledge that you've trained consistently and correctly, your nutrition is spot on and you're going to be comfortable in the clothing that you choose to wear for the race. 

However, one aspect that you may not have put as much time and thought into is your pacing during the race. When training, we often train to an intensity that doesn't exactly reflect what you'll be doing on the day. Ok, we've done the thousands of miles on the bike, often varying between group rides, solo rides and shorter and some harder efforts and we've run huge amounts of miles at MAF or very low aerobic intensity and done some speed work too. But just how do you put all this into practice and pace yourself, holding enough in reserve to be able to execute the strategy that you want to and achieve your goals? It's absolutely vital to your ambitions and race expectations that you pace an Ironman race effectively and efficiently. Hopefully this post will go some way towards giving you an idea of how to do this. I've deliberately left out my thoughts on nutrition and hydration etc because these can be quite an individual thing, although knowing that you have to keep your electrolytes up, that your body will only process 60g - 90g (max) of carbs per hour and that it's sometimes difficult to eat on the run (I'd suggest consuming 75% of your race nutrition on the bike) are all essential factors, but I think that the in depth discussion around those aspects is something for another blog.  

First up, the swim

The swim is (obviously) the first part of the race and although this isn't usually where your race will be "won or lost" and you can be forgiven for thinking it may not have a massive impact on your overall time, but you'd be wrong and the potential is still there to have a poor swim and start off on the wrong footing for what's going to be a very long day out.

You'll possibly be thinking to yourself "this is it, this is where all the months and months and the thousands of miles of training, all those cold and lonely winter sessions are finally put into practice", so before the swim start you'll more than likely be feeling nervous (unless you're a robot) and you'll be hoping that everything goes well, or at the every least you'll be apprehensive or excited and the adrenaline will be flowing. This is when you first need to really focus, just think about the first couple of hundred metres or so of the swim. Are you going to find clear water and take your time, or are you going to get in the mix and draft? Whichever option, don't think too far ahead. As I said, you'll almost certainly have some nerves, so just focus on getting in the water, getting into your rhythm and and making sure you breathe out fully after every breath, controlling your effort and swimming well within yourself. Pushing a little too hard in the swim is so easy to do and you might not feel like you're doing it because of all the adrenaline that'll be flowing and you'll probably not get out of the water feeling tired either, but I guarantee that it'll catch up with you later on. I published in a previous blog about psychology and how it can affect your training and racing. If you're feeling really nervous, try smiling to yourself, talk to people / team mates / supporters and other athletes. This will help to distract you and will help to settle the nerves. Try to focus the nervousness into excitement, this will be less draining on your body and will make you feel energised, rather than lethargic.

When you finally get into the water, be confident in your ability. You've swam this distance (and further) in training, find a bit of clear water or find someone's feet to swim on, and set off, focusing on your technique and BREATHING. With the rolling starts that IMUK employ these days, it's much easier to find some space and avoid getting smashed about and being caught up in the melee of what it used to be like with the mass starts, if that's what you choose to do. You don't need to be swimming in the middle of a bunch, fighting for space, which can be tiring and use valuable energy. Instead, as swimmers pass you, drop onto their feet and draft them, keeping your fingers a few inches from their toes. This is free speed and will definitely help you with your time. When focusing on your technique, don't swim too hard. Swimming isn't like running or cycling where you can look at your watch to see what pace you're doing or to see what your heart rate is so that you can back off if you're going too fast. But for most of us, we tend to swim at a fairly constant pace in training, when doing long and continuous sets, so focus on this and don't go flying off too fast, which as I said previously, is all to easy to do with all the adrenaline that'll be flowing. Don't race off too hard and end up blowing up before the first buoy, if you fly off the line and end up going anaerobic even if just for a minute or two, it can have a big impact on your race. You'll not notice it straight away, but in another 10, 11 or 12 hours it'll creep up on you and you'll definitely notice it then, so it's vital that you control your pace in the swim. Spend the 20 seconds or so during the Australian exit to adjust your goggles (if you need to) have a glance to the crowds and regather yourself, reset and get ready to complete the second lap, by which time you'll probably (hopefully) be completely relaxed and well into the racing mentality. 

Onto the bike

In terms of pacing, this is the most crucial of all three disciplines during an Iron distance race.

You'll probably be buzzing after completing the swim and seeing / hearing the cacophony of noise around the swim entry / exit and you'll probably be feeling great, so you can fully expect another big adrenaline hit. When you get onto the bike though, I can't stress enough how important it is to hold back and not push, especially on the flatter courses. Unlike the swim not being absolutely critical to your success and finish time in an Ironman (to a slightly lesser extent), the same cannot be said of the bike. If you push too hard on the bike, it WILL affect your entire race. A highly regarded coach and very successful athlete said about effort on the bike, “if it feels too hard, you're pushing too hard. If it feels just right, you're probably still pushing too hard. If it feels a bit too easy... it’s just about right”, although obviously this is dependent on the bike course and the hillier courses are harder to gauge. Similarly, if you're riding to a power profile make sure you stick to it, this is crucial. Also, if you know your heart rate zones for on the bike, try your best to control the efforts and not spike too much. That said, for the bike course for Ironman UK in 2019 and some other very hilly Iron distance bike courses you might need to employ a slightly different strategy because of the number of hills. At Bolton it can feel like you're either going uphill or downhill and because of the amount of hills, if you go too easily on all the inclines, the descents aren't long enough to make up that lost time. So I'd say push slightly harder on a climb than you might don in a flatter Iron distance race and then push harder still on the descents, but still riding well within yourself. If you haven't already practiced and done so in training I'd say it's worthwhile riding the first lap slightly easier than the second or third laps, depending on the course. But whichever option you choose, it's important to have one eye on the race as a whole.

Because mental focus can be tiring when you're concentrating hard it's impossible to remain 100% focused on the entire race, so spend the first part of the bike, maybe even as much as the first lap of the course enjoying it. Say the odd nice word of encouragement to fellow racers, or have a bit of craic with some of them, soak up the atmosphere and support on the course, which for Ironman UK is often amazing and generally try and enjoy it because it will help to reinforce the positive mental energy. Although you'll probably have done numerous century rides during your training and often with a run off the back of them, you'll not have run a marathon off the back of a 2.4 mile swim and a 112 mile bike ride in training, so you need to keep that in mind. If you have a good taper during the week or so leading up to Ironman, you'll feel like an absolute machine when you get onto the bike on race day, so this is where you need to be very disciplined with your pacing. At your current fitness levels and with the taper beforehand, you'll probably be able to smash your previous PB's for the bike course, but it would come at a huge cost and you'd probably end up walking most of the marathon. Cramping / blowing up on the run is very often caused by pushing too hard on the bike, even by as little as 10%.

Another very important aspect is your mental strength. Because the race is so long, it's nigh on impossible to stay focused and "in the zone" for the whole thing, so you need to be getting off the bike in T2 as mentally fresh as possible. But if you've spent the last 6, 7 or 8 hours really focused and pushing a tiny bit too hard, you'll get off the bike and will feel shattered and the thought of doing a marathon will fill you with dread. You need to be getting off the bike and feeling fresh enough to know that you can adopt whatever strategy it is that you've set out for the run.

The run, it's in the bag from here

Well, you've swam 2.4 miles, biked 112 miles and now you've just got a measly 26.2 miles to run, until you're at the end of the race 😊. 

Firstly, you'll need a strategy that you're hoping to execute on the run. Even the best athletes will sometimes walk certain sections of the run during an Ironman. I was once told that it's inevitable that we'll have to walk at points of an Ironman run and one of the most important things to do is to make sure our brain to dictates to our body when we walk, not the other way round. By this I mean that for large parts of the run (possibly the majority of it), our body's will be in pain and will be screaming out to stop, but we have to push on and try to stick to a strategy whereby we dictate to our body when we stop and walk, not just when it's telling us to. This is where the long training runs that have been done as a run / walk are vital to your strategy.  If you adopt a run / walk strategy on the run, it can help you massively. Some people run 10 mins, walk 3 mins etc, others run the downhill parts of the run and walk the uphill parts (Bolton is surprisingly undulating). Whatever you do, you need to have a plan A, B and C and sometimes D, E and F. It's rare that we set off on an Iron distance race with plan A and finish still carrying out plan A. There are countless variables and unknowns and for many people doing their first Ironman, the feeling of the progressive fatigue can be unnerving, concerning and sometimes overwhelming, so it's important that you can adapt to what's in front of you and keep a positive focus without too much anxiety. So to have different strategies, particularly for the run leg is very important to your overall plan. 

A friend of mine told me in 2016 that they wanted to try and hold hr zone 2 for the marathon because that's what they'd been doing in training. However, whilst they were able to achieve this for the first few miles, they soon became aware that they couldn't get their heart rate up to anywhere near zone 2 as they started to suffer with fatigue, this is due to the parasympathetic nervous system being a lot more active during the chronic fatigue encountered towards the back end of an endurance race. In addition to that, I also told them, on numerous occasions, that they needed to stop thinking of it as a marathon. It isn't. It's a just a 26.2 miles run and you just get through it however you can. It was only after the race that they said to me "I can see exactly what you meant about it not being a marathon, now".If you've trained properly and stuck to a progressive and structured training plan, this is what you need to put your trust in.

The final bit of advice (which varies massively depending on the individuals opinion) is that if you're a first time Ironman athlete try walking down the finishing chute and soak up the atmosphere. There's nothing like it and the hundreds and sometimes thousands of spectators are all cheering you and you'll never, ever do your first Ironman again, so savour the moment. Unless you're within seconds of going under a big target that you set, walking the 30m of the finishing chute isn't going to make a significant difference to your finish time but will give you a buzz like no other. 

Naturally, all of the above is subjective and many coaches will have differing views and opinions, but I've tried to put together some helpful guidance based on what I've learned as a coach and experienced as an athlete as well as what I've learned from discussions with other coaches, all of whom are highly successful in both coaching and competing in endurance sports.

Remember though, pain is just weakness leaving the body 😊

If you'd like to speak more about your goals and ambitions and how I can help you on your triathlon journey, click on the link below which will take you to my coaching Facebook page, where I can be contacted through

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