Advanced Class: Pacing The Ironman Marathon

I posted this today on the Endurance Nation forum. For hard-core triathlon nerds only…

This morning, I read Tim Cronk’s comments on Dawn Cass’ IM MT race report, regarding the relative value of pace, HR, and RPE during the IM run. I want to respond, but don’t want to hijack Dawn’s compelling report of her marvelous race – which if you haven’t read, you really should: http://members.endurancenation.us/F…spx#233316

So I’m starting a new thread on this venerable topic. It’s often at the top of our minds as we get ready for the big day; you might even say we are obsessed with it here @ EN. First, a warning: if you are heading into your first or second Ironman, you probably should stop reading right now. Whether you are “racing” or “participating”, executing an Ironman is a complicated proposition, with a myriad of opportunities to royally mess things up. The race execution guidance our coaches have developed over the years really works, and is a great place to start (or even stay) if your goal is to survive your first IM, or to see how fast you *might* be able to go.

But at some point, as Tim alludes, metrics become limiters (reins), not whips. I firmly believe that if you want to have the fastest possible overall IM time, you must learn how to read and respond to the subtle, subjective feedback your body is constantly giving you, and use that to achieve, in the case of the run, an overall even pace – the proverbial even split, 13.1/13.1 times about the same. What follows assumes that you have done everything right up to the start of the run: training, taper, nutrition, bike pacing, etc, and are ready to unleash the beast on the marathon.

There is evidence that the best strategy for pacing is an even split between the two halves of the marathon, In my absolute best IM races, I achieved this (I have the mile-by-mile splits in a number of races to document this.) But it’s not just me; looking at the progression of the world record in the marathon distance, we see the same pattern. Each time the men’s World Record in the marathon has been broken in recent years (as well as a recent women’s record), the runner ran relatively even first and second half splits:

True, stand alone elite marathoning is not the same thing as age group amateur Ironman racing. But It does give us some food for thought.

So how to get there? As I said, I’m a firm believer in “listening to your body” to achieve to your potential. (For a quick read on this topic from Amby Burfoot, a guy I went to college with, who won Boston in ’68 when he was a senior: http://www.runnersworld.com/peak-pe…aranteed). Learning that language is not easy, I suspect (I’ve been at for 68 years now), but it is possible. That’s where experience – simply racing a number of times – and following metrics – HR and pace, both during and after the fact – are important. But the end result is really quite simple, in my view. I’ve found my best results when I allow two things to guide me during a race:

• Constantly asking myself the question, “Can I hold this pace for the reminder of the distance?”
• Constantly being willing to slowly crank up the feeling of effort from beginning to end.

People who’ve heard me on this topic before will recognize the following, but I can’t repeat it often enough. An even pace will not feel the same from beginning to end. For the IM marathon, it will start out feeling stoopid slow, about like the warm-up/first mile of a recovery run. From there the feelings progress (miles 3-7)through my LRP during the first third of a long run, into (miles 8-12) my TRP during the middle third of a long run, into a true MP (miles 13-16/7), into feeling like I’m running a half marathon by mile 18, a 10k by mile 22, a 5K by mile 25/5, and like I’m ready to die by mile 26.