What’s it take for a 4:35:00 Ironman Marathon

Ah, the marathon at the end of the Ironman…a 26.2 mile run, after a 2.4 mile swim and 112 mile bike ride…what a whacked idea that is to start off with…who can forget Julie Moss…nobody that watched her: 

Ooouch.  Tough to watch that one.

So to make my 8:00pm dinner reservation on Ironman Race Day, it looks to me that I’m going to need about a 4:35:00 run, or 10:30 per mile run pace…so let’s see what that will take, presuming that I’ve had a smooth swim, and solid bike ride right on race plan.

Of course, by the time that the run comes along, it’s already been a long day…and there are lots of variables that impact run performance.

Starting with Joe Friel in Going Long, he notes 2 rules of thumb:

  1. 40-90 sec. per mile slower than you’ve run in a half-ironman race
  2. within 20 minutes of your standalone marathon time

It’s been a while since I’ve done either.  My last standalone marathon was a 3:58 in December 2006…so rounding to 4 hours that would place my potential ‘then’ at 4:20:00.

The Endurance Nation (EN) folks, are a lot more specific…they base their stuff from the Jack Daniels book, Daniels’ Running Formula, and have extrapolated it to the Ironman marathon distance…Daniels always makes the point that the closer the test distance is to your race distance, the better a predictor it is, and that it presumes appropriate training for the race distance.

First step is to establish your vDOT level, by doing a race test over 5K at least…or 10K…or half-marathon…and enter into a calculator like this.

The EN folks then say that your potential in the Ironman marathon is the E-Pace based on that vDOT value…and they like the 5K test in particular because it’s easily repeatable without trashing your legs.

So for me, to have the potential to run a 4:37:30 Ironman marathon (10:35/mile pace) that would mean a vDOT value of at least 38, and therefore the following test race performance:

  • 5K in 25:00, 8:02/mile pace
  • 10K in 52:17, 8:24/mile pace
  • 1/2 marathon standalone in 1:55:55, 8:50/mile pace

As it turns out, my standalone marathons, put me at about a 39 vDOT then, most recently 2006…for shorter distances in the past, I’ve had it as high as 42, when my actual marathon time said it was a 38…Daniels would probably say that I didn’t prepare enough for the longer distance…I’d say, it’s probably more that I’m genetically skewed towards short and fast, rather than long.   In high school track, I was competitive at 400M, and uncompetitive at 800M, and totally out to lunch at 1 mile.

Final Thoughts

Using the EN approach, only because it has the benefit of a more precise idea…and assuming that it’s valid for the moment…as much as it looks like my vDOT may be there, or close even recently…based on how I’ve run in triathlons in the past, I’m thinking that I’m going to need a higher vDOT at the shorter distances than a 38 to get close to a 4:35 Ironman marathon potential. 

So it feels like a short distance vDOT of 41 to me, which would predict a 9:59/mile E-Pace for a 4:22:00 Ironman marathon…allows me leak a little oil, and still get to 4:35:00…also in line with Joe Friel’s idea of high end ‘potential’.

So looking at it now, a year away, my initial goals for shorter distance race tests would be:

  • 5K in 23:30, 7:33/mile pace
  • 10K in 49:01, 7:53/mile pace
  • 1/2 marathon standalone in 1:48:40, 8:17/mile pace

I’m also thinking I may need to lose a few pounds to ‘buy’ some extra speed to get there 🙂

…of course, this Post is an academic exercise to some extent…my knee ‘issue’ will dictate to a large degree how much run training I can absorb, so not likely to hit the ‘potential’ on the run…although without hitting the test ‘numbers’, no chance at all

…probably will still need a crushing bike ride to be sitting down with a martini at 8pm on race day

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