Doing a marathon this fall and Ironman CDA next June. I am wondering what the rule of thumb is for determining your IM run goal (assuming you have a good bike and all goes according to plan on race day).
I know for me the 1/2 marathon PR + 5-7 minutes formula has been a very
accurate predictor of my 1/2 IM runs. How many minutes should I add to
my marathon PR to get a realistic goal for my IM run?
Depends a TON on bike pacing and run fitness. Also, most open marys are done is much more favorable weather (i.e. early morning in the spring or fall), so take that into account as well (although IMCDA isn’t generally the furnace of Kona or humidity of IMLou). For me, I was between 30-40 mins off my open times, although I think closer to 30 should be one’s “goal”.
I agree, way too many factors involved in a successful IM Mar. 30 minutes is an ambitious, but achievable goal. But, 7 or so hours after the race started you face the Mar. and then the going gets interesting. I’ve been anywhere from 26min. to an hour plus off current open run times.
I remember Gordo saying way back when that the average rule of thumb was 45 minutes, but of course of factors such as weather, bike pacing/effort and nutrtion can weigh heavily. For me, my standalone best is 3:10 and IM run best is 3:53, which falls into the range that Gordo mentions.
FWIW My personal experience:
Marathon: 3:38
IM marathon: 4:16
Like you said a million variables…nutrition, bike, pacing, weather, etc etc
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You already properly qualified the question so I won’t reiterate all the variables that contribute to this, but with the right training and race execution, you can plan on anything from 30 to 45 minutes difference from your open marathon time.
I suggest to all Ironman athletes who are just starting their training preparation to look at their open marathon time and add 45 minutes to set a realistic target IM-marathon finishing time. This will then dictate your training paces for your IM training, which are critical for proper race-day execution.
A well executed race gets you within about 10%. The more fit you are, the smaller this percentage can be.
I remember Gordo saying way back when that the average rule of thumb was 45 minutes, but of course of factors such as weather, bike pacing/effort and nutrtion can weigh heavily. For me, my standalone best is 3:10 and IM run best is 3:53, which falls into the range that Gordo mentions.
With limited experience on the bike, I was in the 45 minute range. Eganski, who is a monster on the bike, was closer to 20-30 minutes.
A well trained for, and well executed race, should be about 20 or so minutes off what you would have done on the same course at the same time of day. There have been some pros get to the 15 minute range, but 20 is a solid number. If you are off that #, then it would be a good idea to look very closely at your prep, pacing, and nutrition to see where you can improve…
Me:
Open Marathon PR in 2006: 3:39
IM2007 4:09
IM2008: 3:52
IM2009:3:47
The key for me was train so much on the bike that 180km at a good pace seemed easy. The final big sessions on the bike in the last 8 weeks were when it all came together - I did several 215km rides followed by 1/2hr runs.
Open marathon PR: 2:56; IM run PR: 3:38
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Open marathon PR: 2:56; IM run PR: 3:38
ha, I can beat that! Open marathon 2:54, IM run PR 3:38. Open marathon was done under ideal (for me, meaning cool to cold - snowed a little during the race) weather conditions.
George
There’s a good chart that gets mentioned from time to time here:
http://forum.slowtwitch.com/gforum.cgi?post=2466287
The thread referenced in that thread is also quite interesting (although a little more controversial).
It was a 30 minute difference for me between open marathon and my one Ironman marathon. But I paced the Ironman marathon very poorly. I ran the first 5 miles much too fast, not realizing. I couldn’t get my Garmin working and they only had kilometer splits. I only know miles, not kilometers. Had I paced it properly early, I would expect the difference to be less.
Marathon (Nov 07): 3:12
IM#1 (Mar 08): 3:41…disciplined bike pacing
IM#2 (Feb 09): 3:51…terrible bike pacing
Figured by IM#2 I would’ve been in 3:00-3:05ish open mary shape (if trained correctly)
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3:12 Mary
3:30 in IM
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All the advice is good advice. Here is the reality, pacing “goals” go out the window once it is time to run. For me a 3:16 IM, was about a 1:33 first half and 1:43 second half - so factor this into the “planning” Good luck
Marathon - 2006- 2:49
IM Marathon - 09 - 3:16
3:12 at IMFL. Warm, flat. Shooting for 2:42 open mary in March on mostly flat, probably cool weather.
Most of the time I hate running and do as little of it as possible.Luckily they made me do lots of it at school so guess some if it is stuck there in my memory.
Mary PR: 3:02
IM Mary PR: 3:22
Double Mary PR: 8:44ish(Ultraman Canada)
100k PR : 9:44ish(Deca olympic triathlon)
I’m a lazy bastard.
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open: 3:25
IM: 3:27
I enjoy running consistent 8 minute miles and still had my running legs after the bike.