How to pace an Ironman triathlonHow to pace an Ironman triathlon is an important questions that is answered with experience, trial and error.

If you have an Ironman approaching though you have a lot on the line.  You don’t want to make costly mistakes that could ultimately result in a DNF and ruin your race day.

This is especially true if you’ve been training consistently and you feel ready. You’ve planned how to taper for an Ironman and now with only days to go you’re wondering how to pace your Ironman.

If this sounds familiar, then great! Today is all about the Ironman pacing strategy. Lets get this right.

How To Pace An Ironman Triathlon – What You Need To Know

  • The swim start will be a melee of arms and legs – be ready for this and have a strategy
  • Swim placement – place yourself near the front only if you expect to swim under an hour
  • If you expect to take over 80mins then place yourself towards the back – slightly wide and back
  • Pace your Ironman swim with an easy perceived effort, find your rhythm and relax
  • Draft on a fellow athlete but don’t rely on them for navigation
  • Consider your transition carefully to avoid making mistakes or forgetting something
  • Start the bike leg with an easy perceived effort (RPE) and hold back
  • Build into moderate effort at later stages beyond 60miles
  • Carefully and smoothly move through transition 2
  • Hold back on the early stages of the run – you’ll feel good once you get your running legs back but hold back
  • Increase your RPE into the second half marathon and specifically the final six miles
  • If you have planned a walk/run strategy or walk through aid stations then stick to it

How To Pace Your Race Using RPE

In a Ironman triathlon pacing makes the difference between a personal best race and not completing the race.

In an Ironman, the importance of pacing is magnified due to the huge distances covered. Your pacing strategy will affect your physical and mental state, your ability to consume fluids and food, your homeostasis such as temperature regulation and ultimately your ability to keep going.

If you over exert yourself too soon in an Ironman race, you will know about it.

One mistake I think too many athletes make is to become reliant on the metrics of heart rate, pace and power (on the bike).

While using these metrics to keep yourself in the correct zone as part of your Ironman pacing strategy is a great idea, the sole reliance on these metrics is a mistake.

By performing sub-maximal fitness tests you can calculate a heart rate and power range to stick to during your Ironman. Modern technology is fantastic! And in addition to this you can use GPS data to check your splits which in itself can be very motivating.

But what if things go wrong?

What if the GPS signal is lost? Your heart rate monitor stops working? Or your target zones turn out to be too high or low on race day?

Variables To Consider When Using Metrics

  1. Cardiac drift, particularly over long course triathlons. Your heart rate will naturally increase over time with fatigue, dehydration, temperature increase and can even be affected if you take stimulants and the natural ‘adrenaline rush’ you get on the start line or whilst visualising success during the race.
  2. Technical issues such as heart rate strap connection, low battery, damage to equipment and loss of GPS signal.
  3. You forgot your gadget!? It happens, and if you are reliant on it, your confidence will take a knock right on the race day.
  4. Heart rate, power and pace are useful especially when considered in combination. Heart rate low? Whats your power output or run pace?
  5. Your goal is to succeed in your Ironman race. Whether you want to win, qualify or just get around. It doesn’t matter what your heart rate says – this is not the success outcome. Will you be saying ‘I maintained 120-140bpm for 8 hours’ or ‘I completed my first Ironman in X hours and I’m really pleased to have smashed my target time!’ What I am trying to say here is that these metrics are almost arbitrary, and the success outcome is your race result.
  6. Gadgets don’t consider external factors that are out of your control. Many athletes need to travel to events and are affected by jet lag. Travel often results in dehydration. Pre race nerves affect HR. Stimulants such as caffein and L-Tyrosine may affect your race. Temperature. Fatigue.

The list goes on. While you can consider these factors, again, sticking to target zones may be unrealistic on race day for a multitude of reasons. Not just that they are unachievable, but on the race day you may feel awesome and maintain a higher power output than expected.

And how you FEEL is what it’s all about. Which brings me onto the most valuable of all the pacing strategies – feel – and the Borg Rating Of Perceived Exertion (RPE).

When deciding on how to pace an Ironman triathlon, or any distance triathlon, the Borg RPE scale is an extremely useful tool.

Research has shown that the Borg scale, which is measured on a 20 point scale, starting at 6/20 for complete rest and moving through the scale to what would be a maximum effort of 20/20.

For practicality the RPE scale is often reduced to a ten point scale with a maximum perceived effort of 10/10.

RPE Scale

RPE Description
1 Sleep
4 Brisk walk / jog
5 Conversation pace but working harder. Sustainable Ironman race pace.
7 Harder with more laboured breathing, conversation is not possible without pausing.
8 10km Olympic distance race pace for more experienced athletes.
9 Hard effort, unable to talk,
10 Super high intensity

Benefits Of Using The Borg Rating Of Perceived Exertion

The Borg scale of RPE is a useful tool that is in tune with your body. While it takes a little practice to get used to thinking about your RPE, this comes with experience.

Your RPE will change with your ability. An experienced competitive triathlete might be able to maintain an 8/10 RPE for an olympic distance triathlon. In contrast a novice would be better off – and only able to – maintain a much lower RPE.

I’ll discuss specific Ironman pacing strategy in detail later in this article. Before I do though I want to let you know that despite being a simple tool there are many benefits to using RPE.

12 Benefits Of Using RPE In Conjunction With Other Metrics

  1. RPE is free
  2. It is reliable and always there
  3. It gets easier and more accurate as you practice using it
  4. It is in tune with how you feel and accounts for the other external factors previously discussed
  5. It is very closely correlated with other metrics such as heart rate
  6. There is no ‘lag time’ as with HR. So for example if you’re performing a 20” maximum effort interval training at RPE10, your heart rate response would lag behind the effort. RPE is there – no lag time
  7. RPE is not affected by external factors like pace and HR is. If you have a target pace or HR but the weather conditions or terrain are extremely challenging (wind, heat and hills), you won’t be able to sustain that target. By knowing your sustainable RPE you have a backup pacing strategy.
  8. You get a feel of what is possible
  9. RPE can be linked with other observations such as RPE + Power output + the ‘feel’ of the pressure under foot on the pedal at a certain power output
  10. If your RPE is low and other metrics high, no worries you can up your game
  11. If your RPE is high and your other outputs low ask yourself, is something wrong? Take it a bit easier and things may get better.
  12. RPE is the most reliable metric of all, and it pays dividends to play close attention to this and to become attuned to your body. Particularly in an Ironman.

Examples of RPE In Ironman Pacing

If you set yourself a pacing strategy with a target RPE of 5 but you find your HR is higher than expected, that’s ok, you’re probably experiencing cardiac drift and so aim to maintain your RPE5.

If you have a target power of 120 Watts at RPE 5, but you are only on RPE 4 on race day, you could consider increasing your wattage to reach your target RPE.

Whatever you do decide to do, I don’t recommend exceeding your target RPE, even if your other metrics are low. This is particularly important before the first half of the Ironman marathon has been completed.

In a nutshell, don’t dismiss the use of RPE because of its simplicity. Embrace the use of RPE in your training and racing.

How To Pace The Ironman Swim

  1. Position yourself strategically to match your ability. You don’t want to be rushed into swimming too hard. And you don’t want to be trampled or held back.
  2. While your pre race nerves may increase your HR, your RPE at this point should be low; 4-5/10.
  3. Working harder, particularly in such an important technically challenging sport as the swim, you will be better off focusing on efficiencies in the water; draft, sighting to stay on course, efficient swim style, low RPE.
  4. Increase in effort may pay off if it is a very cold swim and you are beginning to suffer in this respect.
  5. Let the fast ones go – don’t race or engage in aggressive swimming as this is extremely inefficient, you may swallow water / air causing GI distress later and your legs will sink as you gasp for air. Let them go.
  6. Hold back – gaining 5-10 mins by working too hard here may lose you an hour later in the race.
  7. Stay relaxed, enjoy your swim.

How To Pace The Ironman Bike Leg

  1. Hold back with a low RPE, and even lower if you are suffering GI distress. As blood is taken away from the stomach in high intensity exercise (if you worked too hard during the swim) you will need to regain homeostasis now.
  2. A low RPE4 now will allow you to take on fluid. Just water, particularly if a salt water swim. Sip slowly for a few minutes until you feel better.
  3. Maintaining the low RPE4-5 during the first 20-50 miles will allow you to ‘front load’ your nutrition, and replace lost calories from the swim.
  4. Let others go. This is an individual sport so leave your ego at home. If you have trained properly you will likely feel very strong, and the younger athlete in me has in the past made the mistake of racing others. Only to pay in the later stages of the race.
  5. Remember the marathon is ahead, so a strict pacing to match your ability and experience will pay off.
  6. If you are more experienced, a slight increase in RPE to 6 or even 7 in the latter stages of the bike (80-112miles) may be possible.
  7. Reduce your RPE in time for the run.

How To Pace An Ironman Marathon

  1. The Ironman marathon is where the race either comes together or falls to pieces for so many athletes.
  2. If you overdid it on the bike you could pay dearly here.
  3. Hopefully you have performed brick training sessions and these will pay off now.
  4. If there is extreme heat, you might have to consider reducing your RPE further.
  5. Consider the marathon in 4 parts. The first half marathon. The second half marathon. The final six miles, and the aid stations.
  6. Maintain a low RPE and run well below your known half marathon pace. If your bike was well paced you might feel awesome at this point, but it would be a mistake to go too hard too soon.
  7. Take time to get your running legs back.
  8. If your plan is to walk/run, stick to this plan from the very beginning, and not in response to fatigue in the later stages of the run.
  9. Ensure you take on fluids, electrolytes and energy at the aid stations, and run at an RPE that allows this. Slowing down at aid stations to ensure consumption of fluids/nutrition will pay off.
  10. Build your RPE in the second half marathon only of you feel great. If you have been going at RPE 5, you could build to RPE 6 or 7. More experience will allow for a higher maintainable RPE.
  11. In the final 6 miles, the motivation of knowing you’re nearly there will spur you on. If you want to you can take a risk and build your RPE to a 7 or even 8. If you went too hard too soon you could be struggling at this point, so maintain a low and consistent RPE.

Putting It All Together

There is so much to consider, not just how to pace an Ironman triathlon.  When it comes to putting it all together, I go through a five step process with my clients that really helps build confidence knowing that they are following a strategy.

Firstly, planning your triathlon, goals, mindset and everything in this respect is often neglected. Forming outcomes, defining success and developing you big motivation for racing an Ironman can really help.

Assessing your fitness on a regular basis from the start of your training plan is my next step. This shows progress throughout, again increasing reward and motivation. In addition helping to plan what is a realistic goal.

Triathlon nutrition plan is the third fundamental step, and again largely ignored or given a last minute thought with no real strategy. I get triathletes to consider sports nutrition as well as eating for general health and wellbeing.

Training is the obvious stage in triathlon. I take an intensity based approach to training that has two benefits.

  1. Increased fitness in less time spent training – particularly important for long course triathlons and for those who are injury prone.
  2. Easier logistics for the kind of triathlete I work with – the time strapped ‘real world’ triathlete. To be fair, that’s most age groupers, isn’t it?

The fifth and final stage, which again is often ignored is the race itself. Executing your perfect race doesn’t happen without thinking about it. I guide triathletes through their perfect race. The difference between having the perfect race and not finishing is all in the planning.

So, that’s it for today. This is an insight into how to pace an Ironman triathlon, and now you need to consider what is going to work for you, your experience and your goal.

Online Ironman Distance Triathlon Training Plan 336x280If you did find this information valuable you might want to take a look at the online Ironman triathlon training plan that I offer.

It is a 12 week training plan that follows the five steps described above. In addition it takes you through an additional 4,8 or 12 weeks of ‘lead up’ to the main training plan.

As always it is designed for the ‘real world’ triathlete with an intensity based low volume approach to training. Find more details here, or get in touch using the contact form. In the meantime, happy Ironman training. Nico.