Marathon vs IM Marathon estimations

pcsronbo · Feb 28, 2011

So first of all, let me preface this by saying I've never DONE a marathon. My first one will be 6/26/11 during my full IM.
 
So I'm curious what you guys things as far as reasonable expectations... my current 13.1 PR is a 11:48 pace. Which is totally useless because it's old. I did 12.2 miles yesterday, in z2 (not z4 like my PR) - at a 11:28 pace. I could easily have dropped to an 11 (z4). I've been knocking out long runs at that pace, or better, pretty consistantly lately so I don't think it was a fluke.
 
So, let's just say 11:00 is my 13.1 stand alone pace. According to McMillan, than means a 5:01 marathon. I have to say, that seems pretty spiffy fast for the likes of me.
 
What should I set my head around for an IM marathon? 6hrs?
 
I fully realize this is predicated on
a) nothing major going wrong during my IM
b) weather being reasonable
c) not frying my stupid azz out on the bike
d) implementing my hydration/nutrition plan reasonably well
 
I get that those could easily override me and send me to walk the whole 26miles.
 
But just curious to hear from those who've done both and how it lined up?
 
p.s. my first IM is not "for time". this is more in expectation management with the family and just overall planning the logistics of my support team

maggie d · Feb 28, 2011

it's really hard to say. 
my first IM: my marathon was about 20 minutes slower than my slowest marathon, and I had ran 6 marathons before my first IM. 
my second IM: was my second best marathon time! 
my third IM: was about 30 minutes slower than what I would predict my time would be if I were to do a stand alone marathon. 
 
I would say, add about 30 minutes to what you think you could do a stand alone marathon in. give or take of course. 
 
for me, my legs are already warmed up. and it's different muscles than what I was just doing on the bike. 
if you have to walk, walk very fast! just keep steady, and do not go out too fast. you will feel surprisingly good coming out of T2, but then it hits pretty quick. nutrition is also of course a huge factor. I personally focus on hitting my nutrition on the bike, as my tummy is always iffy as to whether it will accept food/gels by the time the run comes. eat, eat, eat on the bike!!! grab something at each hand up, banana, gel, power bar, or eat you own food. the aid stations come about every 10 miles, so it's a good reminder of when to eat. or maybe you have your calories in your bottle? either way, shoot for at least 200 cal/hr; or whatever has been working for you. just don't forget to stay on top of it, it's hard to make it up later. 
 
btw, walking the whole marathon is okay too!! you are right, your first should be only about finishing with a smile and enjoying it! having your family there to support and cheer you on is great!!!! I think that you will be able to use that as a big pick up and keep your legs running. can't wait to see how it all comes together, you've been working hard for this!!! you got this.

Stitcher · Feb 28, 2011

My first marathon was San Antonio....6:20-ish and I think that through inattention and poorly marked course that year, I may have honestly not done the entire course. So, I put that as an (*) by the time.
 
My second marathon was Richmond.... 6:08 -- Was in line for a sub-6 hr, hoping for 5:30-ish, but less than stellar race day conditions that were far from the trending conditions of the previous 5 weeks derailed that one.
 
My third marathon was in IMFL.... 6:35-ish or so. I felt GREAT during the whole run. Emotionally and physically. I was tired, but not the kind of tired that causes you to be mentally slogging through it. I got slower as the distance went on, but it didn't drag me down the way my slowing of pace in the first two 'thons did. I finsihed running strong. According to my mom (the official arbiter on all things me), I looked "bad" during the first two 'thons, and GREAT during IMFL. Go figure.
 
I agree with Maggie..... my legs were warmed up.... I fueled well on the bike (aweomely, in fact...everything went fabulously)..... I had a great race day prior to the IM marathon. I had fuel with me on the run, but ended up not using most of it, and relying on the course provided stuff. My gut was fine, but my taste buds were just sick of the flavor. So, I was able to get what I needed from the course. 
 
If you think that you'll have issues with whatever is provided on the race course, you may have to be more obsessive about what you carry on your run portion. I was lucky, I think. 
 
My fourth marathon will be Marine Corps, this fall. We'll see how it compares to the others.
 
I'll be interested to hear what more runner focused folks will have to say. Running is definitely my weak sport of the three, so taking my experiences as anything other than advisory is a bad idea.

Alaska Mike · Feb 28, 2011

As others said, that's a tough question. My advice to you is to not even worry about times on your first IM. You should be going by feel by either HR or RPE by the time you hit the marathon. If it feels tool hard, go easier regardless of what the pace is. Okay, now to actually answer your question...
 
The general rule of thumb is 30 min slower than your stand alone time. I've never gotten close to that. In 08, I ran 2:47 at Boston and 3:29 at IMMoo. In 10, I ran 2:40 at Boston and 3:38 at IMMoo. Go figure. For me, the stand alone and IM marathon are two completely different beasts. I obviously don't feel like I've run anywhere near my potential in an IM marathon. I run my stand alone marathons in z4, right at the edge of threshold. I run my IM marathons closer to z2/z3. I just come off the bike too tired and so the IM marathon ends up being a long, slow run. But I do run the entire thing.
 
I think if you have a strong running base then you can hold your z2 pace through the IM marathon. Not sure if you have a good enough base yet, it wouldn't surprise me to see you do some walking. I'm hoping I'm wrong there, but there is no shame in it. If you're doing z2 runs at 11 1/2 min/mi now I'm going to guess your IM marathon time somewhere around 11 3/4 to 12 min/mi. Yeah, its that tough.
 
Mike

Yo Mikey · Feb 28, 2011

This is my experience, prefaced with the usual ‘grain of salt’ boilerplate…
 
 
My slowest (and 1st) marathon time and the average of my IM marathon times show near dead on in comparison:
Slowest marathon -- 5:28:xx
IM marathon avg. -- 5:31:xx (5:23, 5:22, 5:46)
 
When comparing to my fastest marathon of 3:39:xx, the variance is wider than any guidelines or rules of thumb. I think if you are hugely trained for IM, then you are more likely to be closer to these rules. I was still in the experimenting phase with regards to IM and trying to figure out how to properly train for and more importantly race these and was working out the bugs. When training for my best marathons, I trained specifically for those and nothing else.
 
For Ironman, expect to be tired in the run, so train to be strong on the bike. A strong and controlled bike leg will lead to an easier run leg.
 
Also, teach the family how to decipher the Ironman Athlete Tracking web page so they can estimate when you’ll be hitting viewing hot spots, transitions, or more importantly the finish, this is in the event they will be doing other things while you’re out kicking ass on the course!
 
Yo

AdCo · Feb 28, 2011

I did Boston in 4:20 last year, then I did IMLP i 5:27ish.. There will be lots of variables, heat, sun, wind, rain, and nutrition. I found that once I started walking and knew I was going to finish, I just sort of lost the will to run. Plus my tummy wasn't happy. Once you start walking, it is easy to just chat with someone. Since you are a strong biker, you will probably come off the bike with plenty of time walk a good 7-8hr marathon. I would run as much as you can easy and just enjoy it. Of course, if are up against the clock, kick ass and finish strong. I would bet you could easily walk it in 6.5 hrs so I bet you can do 6 no problem.

niemsco · Feb 28, 2011

Take a solid half ironman marathon time. Double it. Add 30 minutes. That's your potential. That is something more or less what some calculators I've used said. I've known people where that is pretty close. I haven't run to my potential yet.
 
OR This:
 
<a href="http://forum.slowtwitch.com/gforum.cgi?post=1062155" target="_blank">http://forum.slowtwitch.com/gforum.cgi?post=1062155</a>
 
OR some say you should be able to run your E-pace in an IM Marathon. So figure out what your VDOT is if you don't know and estimate. Some fun with numbers for you.

jkaiser20 · Mar 2, 2011

Ronbo,
 
you have done 1/2IM and 1/2 mary, haven't you? My memory ain't what it used to be.
 
For me, I did a 2 hr run in a 1/2 IM. At the time I was probably in easy 1:30 stand alone 1/2 shape. A year later I did a 4:30 IM run, and I was in probably 3:20-3:30 stand alone pace. So for me the 30 min holds for a 1/2, but 60 for a full. I was very pleased with both those Tri runs, and felt I had given it a good effort.
 
In my opinion, for you (and most others who are thinking 14+ IM time) the marathon time is less about physical ability and more about mental stability (assuming a non-stupid bike). After 10 hours, the mental piece plays a huge part. Like Adco said, you start getting into the "wee! I'm going to finish" mode. It is easy to do, and you are happy across the finish, but the post IM blues can suck.

pcsronbo · Mar 2, 2011

Yeah, I've done both. 13.1 PR is 2:34 (Ronbo v1) and HIM PR is 2:42 (Ronbo v3) - but there was a lot changes in "me". I did a 12.2 mile run last weekend in 2:20 - I could have done maybe a 2:20 HM now pretty easily. At this pace, I'm hoping to clobber the HIM PR here either in March or May. But who knows...
 
Never done a full.
 
So if I double each - 4:40 (est HM x 2) and 5:24 (est HIM x 2). I'd be friggin thrilled for a 5:24. I would not be surprised for a 6-6:30.
 
Mental, I guess I can't say now, as I've never done it. In every HIM I've had a dark time during each, but as I do them each gets shorter and easier to handle. So I'm totally planning on a dark time or two on the full and fully planning to kick it's living azz and have some ammo in the toolbox to help combat it. Sayings, friends names, and so on.
 
I am for sure watchful of the post-IM blues... Next day I'm meeting up with the PNW in Seattle, day after I get on a disney cruise to Alaska for a week, then when we get back a Portland meetup, then home. I have nothing on the schedule but hope to WANT to do Cyclocross this fall (and get a new bike). Or learn to ski. Or both. Whatever I want

pcsronbo · Mar 2, 2011

I don't have a deep base in the run. Especially running the way I've been running now. but we're working on it.
 
I'd be thrilled to do 12's and I'm not ashamed to walk some. Actually will likely plan to walk the aid stations, just to change up the muscle use. 

<div class="quote-container">Quote:
<div class="quote-block">Originally Posted by Alaska Mike <a href="/forum/thread/72807/marathon-vs-im-marathon-estimations#post_1986111"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style="border-bottom:0px solid;border-left:0px solid;border-top:0px solid;border-right:0px solid;"></a> I think if you have a strong running base then you can hold your z2 pace through the IM marathon. Not sure if you have a good enough base yet, it wouldn't surprise me to see you do some walking. I'm hoping I'm wrong there, but there is no shame in it. If you're doing z2 runs at 11 1/2 min/mi now I'm going to guess your IM marathon time somewhere around 11 3/4 to 12 min/mi. Yeah, its that tough.
 
Mike
</div>
</div>

1Topodope · Mar 2, 2011

Hey ronbo!
 
I don't have any comparison data to offer...I am just starting on my first HIM! Just curious as to what your longest run will be before your IM?

Heather H · Mar 11, 2011

Hey Ronbo! I went over this kind of stuff endlessly last year. For me, all those estimates everyone talks about came really close. 1. best HIM run time x2 + 30 min (I was 10 min slower) 2. average (only one in my case) full marathon plus 30-40 min. (I was +35 min). 3. for overall time- HIM PR x2 plus 1 hour (I was 7 min. faster). I realize those don't work as well for you since you've gained a ton of fitness and not raced much in the last year, but if you do a HIM before the big day, you can crunch the numbers then.
 
I'm excited for you!! You're going to have so much fun!! <img alt="biggrin.gif" src="http://files.kickrunners.com/smilies/biggrin.gif"> Hope training is going well and you're not getting too tired yet!

pcsronbo · Mar 12, 2011

1topodope - not a clue - CC won't post my schedule more than a week or two out so... who knows. I'm doing ~14 tommorow in 2:40ish... I've done 2x1:30's already... and it's March (race in June). I'm curious too and CC isn't sayin nutin! (which is normal - she wants to see how I adapt and so on). With all the changes going on in my running with orthotics and form and so on over the last 3 years - I suspect she doesn't know and will just keep pushing me a bit at a time to see how I handle it
 
heather - racing a HIM in a few weeks - and CC just told me I'm gonna race my ass off - so I'm gonna find out

Marathon vs IM Marathon estimations

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