Pacing Your Ironman Run

Pacing Your Ironman Run

When it comes to Ironman distance events, PBs are invariably determined by the quality of the run. Sure, how well you perform on the run will depend on many factors which will vary depending on how you’ve managed the swim and the bike, but really your management of the run is crucial if you are going to achieve the finish you are hoping for.

You will often see athletes who have been consistently placed in the top 50 throughout the day buckle half way through the marathon. Their pace will drop and athletes who’ve been lagging many miles behind throughout the day will end up finishing ahead of them.

The question is: why?

The Answer: because they don’t pace the run correctly.

Your Ironman Pace

It doesn’t matter how quickly you usually run a normal marathon. The Ironman race is a completely different proposition. Even if you’ve fuelled and hydrated your body in the best possible way, your glycogen levels are likely to be very low by the time you start the run.

Start Slow

When you start your run resist the urge to reach your ideal race pace. Even if you feel like you can go faster, hold back. You are far better off sacrificing 20 – 30 seconds per mile for each mile during the first half of the run if it means you can finish strong.

Don’t Be Afraid to Walk

Another way to make sure you have enough energy to finish strongly is to take enforced walking breaks. If the course has steep hills, walk up them. It won’t cost you much time but it’ll save you a huge amount of energy. You should also think about walking at each refuelling station. This will not only ensure that you are able to recover after each mile, but it will also help you take on the fuel you need to complete the final miles at a reasonable pace.

Focus on Technique

When you get tired you will inevitably develop technique flaws. Your arms might drop or stiffen, your head might drop and your back might arch. All of these flaws will cost you energy, cause discomfort and possibly lead to injuries. When you are struggling with your energy levels and willing the next mile marker to come to you, focus on your technique. The mental exercise of correcting your posture will not only save you energy, but also give your mind something to focus on apart from the shooting pains in your legs.


It doesn’t matter how much training and preparation you do for an ironman run, if you don’t execute it in the right way on the day of the race, you will be disappointed with your result. Follow this advice and you stand the best possible chance of finishing strong.


What do you think? What are your top tips for pacing the Ironman run?