Ironman Triathlon negative-split strategy

Incorporate this Ironman Triathlon negative-split strategy for the best possible race result.

For those of you unfamiliar with the concept of negative split pacing in an endurance race, it basically refers to running the second half of an event faster than the first.

For example it you were to run a 4-hour marathon and the first 13.1 miles took you 2:02 and the second 13.1 miles took you 1:58 than you ran a negative split marathon.

There are several very good reasons why this strategy would be very beneficial to Ironman Triathletes. This is especially true for the novice Ironman and those who have done a few Ironman races and hit the invisible wall big time somewhere late in the bike or in the marathon.

Take control of your Ironman

It is the concept that you begin each discipline in the Ironman slow and easy and well within your capability that is most important to grasp and not so much that you split the swim, bike, and run into equal halves.

Although Ironman Canada no longer takes place in Penticton I will use the IMC 2012 swim course as an example. No matter if a swim course is one-loop or two-loops or clockwise or counter-clockwise the way the Ironman swim should be approached does not really change. It is still going to be 2.4-miles no matter what the swim course configuration is.

It you take 3000+ rested, emotionally charged people who have trained for months or perhaps years to be standing on the fittest piece of real estate in the world at that particular moment you are sure to have heart-rates rocketing out of control.

Even before the race has begun those with high heart-rates are putting themselves at a serious disadvantage. An out-of-control heart-rate is a great way to begin burning off valuable energy that I can guarantee will desperately need later in the day.

It you do not have a race strategy in place and the discipline to stay with it, chances are that when the gun sounds you are going to get caught up in the testosterone-charged atmosphere and go out way too fast.

However if you adopt the negative-split strategy and know long before the race starts that you have a plan in place and will be going out nice and easy with a controlled heart-rate you are much less likely to get caught up in the emotion of the moment.


When the cannon sounds to begin the swim, the trick is to go out even slower than you are capable of and let your body settle into a controlled rhythm that is encouraged by your long, slow, swim stroke. If you combine this with taking an outside line away from the traffic as I suggested in my book “Ironstruck…The Ironman Triathlon Journey” (Ironman swim strategy) you will have a perfect start to your Ironman.

In the case of Ironman Canada, it consisted of two right-hand turns. The first leg was 1612 meters, the second 450 meters, and the last leg 1800 meters.

swim course map for Ironman Canada

Regardless of the course, start the swim easy and pick it up a little in the later stages

For example in Ironman Canada, I would’ve suggest waiting until just after the second turn before picking up the pace a little.

If you have controlled your emotions and stuck to the plan to swim the first half or more of the race well within your ability range, then you should be feeling really great as you make the final turn. As you pick up speed others will be slowing down and in many cases struggling and already burning off massive amounts of energy.

If you are doing a two-loop course and are new to the Ironman open water 2.4-mile swim or have struggled with it in the past, taking the first loop(and perhaps part of the second) easy and controlled will most likely give you an overall better Ironman final race result as it will set the tone for the rest of the day.

Keep in mind that even though you are picking up the pace a little and swimming the last 1800 meters or so at a faster pace than the initial stages of the swim, you are still not crossing the line into anaerobic territory but remain in your aerobic zone.

This in turn will keep your heart-rate down, conserve energy, and set up a more seamless transition into the 112-mile bike course.


About the first five times I did Ironman Canada I fell into the same trap. I would get on that bike and pedal like Hell until I simply ran out of gas and hit the wall. From there the rest of the race was a death march.

Why did I do it? Partly because I never had any race plan in place to start with, but mostly because it was what everyone else was doing.

If you adopt the negative-spit strategy you will know months before the race begins that you will not be falling into that same trap. You will leave that bike transition area calm, cool, and collected and once again will bike at a pace that you can easily maintain and at the same time keeping your heart-rate well in check.

Conserve your energy from the beginning and later pass those who didn’t.

You will not worry about the hundreds of bikes blowing by you because ultimately you will be catching the majority of those same people later on in the bike or perhaps on the marathon course.

As you reach about the halfway mark of the bike course you should be settled into a comfortable spin and perhaps begin to pick up the pace a little. Although you may be tired you will be far better off than if you had gone out too fast and had nothing left in the tank at all.

At this point you should feel pretty good about yourself. You had a great controlled swim and you are through half of the bike course with a firm handle on your heart-rate and your pace.

If you have raced well within the limits of your ability you will most likely begin passing people who are running out of gas. Yes, some of those same people who went blowing by you way back in the early stages of the bike.

As you enter the closing stages of the bike there’s a good chance that at this stage you will be cycling as fast or faster than you were in the very beginning. Either way, you have managed the bike course brilliantly and will not be going into the Marathon completely out of energy.


Most people might say, “I only have one speed in the marathon and that’s dead slow!”

There’s nothing wrong with that.

Just do what you can. Run as much as you can early on because this will take a huge chunk out of those early kilometers. Walk the aid stations and run the best you can in between them if you don’t feel you can run from start to finish. That’s a good sound strategy.

If you are an exceptional runner and feel strong and have no problem running than once again run easily and well within your ability. You have managed your race very well up to this point and will have 80% more energy than all those people on the marathon course who you continue to pass by the dozens and perhaps hundreds.


After about 200 you will tire of counting the people you will pass if you have raced smart from the moment the gun sounded.

If you feel strong and in control at the halfway 13 mile mark of the run this is without a doubt the place to go for it. If you are trying to do well in your age-group or perhaps to qualify for Kona, this is the best place to put the pedal to the metal. There is no way in Hell you could do this if you used up your glycogen supply and hit the wall out on the bike course somewhere.

Most people will be struggling just to survive and reach the finish line and they will most likely be in a world of hurt. I know because I was there so many times before I figured it out. If you have done everything right up to this point than running a negative-split in the marathon could well be what makes all the difference in you reaching your Ironman Triathlon goal.

Without a sound strategy going into the race you could well be walking most of the marathon and believe me, you don’t want to go there.

If you have used this strategy from the beginning until the marathon course and are still struggling a bit, just imagine what shape you would be in if you had raced out of control from the beginning. Either way you will come out ahead by adopting my negative-spit philosophy.


1) You run your own race: From beginning to end you are the master of your own fate as you do not let race circumstances or those around you dictate how you run your race. You know before the gun goes off what your strategy is going to be and develop the self-discipline to not deviate from it.

2) You burn fat for fuel: By racing well within your ability and keeping your heart-rate in check from the minute the swim starts you are burning fat for fuel as opposed to limited stores of glycogen. It is racing out of control that uses up glycogen far to quickly and results in hitting the wall long before the race is over.

3) You enjoy the Ironman experience a lot more: Many people get the idea in their head that being in the death march and suffering out on the Ironman marathon course is unavoidable and is all part of the race. By using the negative-split strategy you will no doubt enjoy the Ironman experience a lot more and will suffer far less.

4) The emotional and psychological advantage: In about my seventh try at Ironman Canada I finally got it right and began to count the people I passed on the Marathon course. I gave up after over 300 of them as there were so many it was a chore to count them all. I can’t even put into words what an advantage it is to manage the Ironman properly and pass people in all three disciplines. It is a huge lift and inspires you do keep right on going all the way to the finish line.

5) Have your best possible Finish time: You may be doing your first, third or seventh Ironman, but adopting this much wiser way of tackling the Ironman might well be the answer to having your best possible Ironman finish time result.

**Just a reminder……I used Ironman Canada as an example for the swim but using a negative-split strategy will work for any Ironman Triathlon in the world. All you have to do is be sure and start out easy and within your ability and control your own race from the minute the race starts. You can decide by looking at the course maps of your particular Ironman exactly where you might begin to pick up the pace in the swim, bike, and run.

Read the IRONMAN DEATH MARCH and get a better understanding of what is in store if you do not have full control of your energy levels right from the minute the gun sounds.

2 thoughts on “Ironman Triathlon negative-split strategy

  1. This article was very useful for me – I just did my first ironman, Embrunman in France. All of the tips were great! It was hard being passed by so many people during the first half of the bike leg, but I got most of these places back in the end (because I could actually run the run leg)!
    Thanks a lot!

    • Thank you for your comment and congratulations on your accomplishment.

      I put a lot of thought into this article(as I do all of my articles)but this one was far more detailed then most as I believe it is at the very core of success for people taking on the the Ironman for the first time or for those who have done a few and keep hitting the wall.

      You are exactly right…….it will seem like everyone in the race is passing you, but it’s a long day out there and in the end you will be the one doing the passing. You will pass people by the hundreds simply because you are running and they are walking.

      Of course, you already know that first-hand.

      Best of all, you will most likely enjoy the experience a whole lot more. IronStruck Ray

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