Comparing IM Marathon times to standalone times.

JeremyBehler

I know it's hard to predict finishing times for the bike leg of  IM based on wattage, etc, but I would think there's a higher correlation between IM Marathon times and standalone times, assuming good IM execution.  Any thoughts on this?  My VDOT would indicate a 3 HR marathon, but my PR is 3:10.  Is 1 minute/mile slower for an IM pace a good estimate? 

charris

Here's a spreadsheet that you can play around with (all the usual disclaimers apply):

http://sites.google.com/site/garminpower/predict

 

"Assuming good IM execution" (in all four disciplines) is the key.

 

As for why your VDOT from a shorter distance predicts a 3 hour standalone but you ran a 3:10, the disclaimer with most calculators is that they assume you've trained appropriately for the distance.  "Trained appropriately" in the case of the marathon generally means a boatload of miles.  This explains it pretty well:

http://www.hillrunner.com/jim2/id70.html

 

 Thanks.

mancona

The general agreement around here is that you should be able to hold the Easy Pace based on your VDOT for the ironman marathon. The delta betweent the two will be different depending on you VDOT.

I personally like to use a half marathon about 12-16 weeks prior to an IM to establish my target pacing...then validate this with training and race simulaition.

Simply get your VDOT form the half marathon, then check the easy pace for that vdot and that is the pace you should be able to hold for the ironman run.

There is very specific and detail pacing guidence from RnP on this in the Wiki and some podcast with more details.

Chris G

 Pace estimates are always to be taken with a grain of salt but this is especially true with IM "run" splits.  The IM run is just a really strange place to be.  It is just plain hard.  Very few people ever execute it remotely well.  Every IM is littered with people that could run a 3:00-3:15 open mary any day of the week walking it in over 4 hours.  So much of the IM run comes down to suckitupituide it is really hard to quantify.  How much are you really willing to suffer when it comes right down to it?  It easy to think you will give it everything, never give up, etc blah blah.  Almost everyone feels that way a week before the race.  About 8 hours in however it becomes easy to not care all that much "i'll just walk a little bit".  The "one thing" you are going to rely on when the body debates the mind at mile 18 is key.  Problem for a lot of folks is that the debate is over long before they get any where near mile 18.  Even worse for first timers as you are very likely in a position you never have been both physically and mentally by the time you get deep into the run.  Its just hard to say what will happen.  

As for predicting 3:26, sort any IM results by run time.  3:30 is very rarified air.  There are few if any people who run under 3:30 that are not in the top 100 finishers overall. No reason you can't run sub 3:30, I know people that have run that fast in their first IM which was their first marathon.  I also know a bunch of people that have run 2:50 open marathons who have never broken 3:30 in lots of attempts.

Just for an example, at IMFL last year which has about the "fastest" run course of any, there were no 35-39 year old men that ran 3:30 or less who did not finish in less than 10 hours.  A lot of this is covered in the TSS discussions but there is really no way to ride easy enough to save run potential as the longer you ride the more it hurts regardless of how easy you are pedaling.

This post got a little more depressing than I intended it to be.  Regardless, good race execution, meant good bike pacing and nutrition as well as starting the run at a pace that feels way too slow will not remotely guarantee you a run any where near your potential.  All that will however put you in a position where it remains possible for you to have a great run if you are willing to turn yourself inside out and keep running long through the dark parts 

 

http://ironmanflorida.com/results/

mancona

Chris brings up some really good points. I have yet to execute an ironman really well, but feel like I have done a decent job. That said, I have run multiple sub 3 hour open marathons and gone under 2:50 and my best IM run is 3:22. Most calculators out there show me as a 3 hour ironman runner but I haven't got close due to poor execution or just because a lot can happen during a long day.

That said, I know a few people that have slower open marahons than me but have managed to get thier ironman run within 20 minutes of their open.... those folks are far and few better and I believe the three I know personally have each done at least 8 or more ironman races (i.e. they have the execution thing figured out).

Steve West

Here's a thought from a total noob (my longest race: HIM)....

Matts best open to best IM (2:50 to 3:22) is 19% inflation.

If I was as well trained as Matt (I'm not) and could execute as welll too (I dont know how to), my never gonna get there best time would be:

My best open 3:30 + 19% = 4:09 What might be possible for me but still a long shot and requires ninja like execution: 3:30 + 30% = 4:33

If that logic holds we could calculate a range like this using your 3:10 best

3:10 + 19% = 3:45
3:10 + 25% = 3:57
3:10 + 30% = 4:07

Is there any merit in thinking this way?

charris

This is why I found playing around with the calculator so fascinating.  To me, it demonstrates in pretty black and white terms how even if you're really flippin' fast in the standalone run, and even if you execute everything leading up to the run really well, and even if you execute the run itself really well, your time is still going to be pretty "pedestrian" relative to standalone run times.

E.g.:

3:00 IM = 53.6 VDOT

75% 3:46:19

80% 3:32:10

EN guidance: 3:34:21

 

3:15 IM = 48.9 VDOT

75% 4:03:50

80% 3:48:36

EN guidance: 3:50:30

 

And for Matt (not sure what his current ninja VDOT is, so working backwards from sub 2:50 for demonstration purposes):

2:49:55 = 57.4 VDOT

75% 3:34:02

80% 3:20:40

EN guidance: 3:23:00

 

From a lot of reading, it seems like 80% of T pace is about as good as you can reasonably hope to achieve if you execute really well throughout and bury yourself.  Very few people do either of those things, never mind both.

 

As with everything, there are freaks of nature, but they're the exception and not the rule.

Al Truscott

Chris and Matt have it covered here. I just want to add a thought on suckitupitude. I'm one of those who has the execution thing pretty well figured out. My best stand alone marathon, in 2004, in ideal conditions (net slight downhill, flat couirse, weather in the 40's) was 3:27; my best IM marathon 5 years older, 20 degrees warmer was 4:01. In that race, I was trying to catch someone who left T2 19 minutes ahead of me (I was in second).

But unless I have a REALLY good reason to work it, I will always go slower, and that can be worth as much as 15 minutes. E.g, six months later, I knew I had a lock on my  goals for the race (1st place AG, course record), and I just could not push myself to go to far beyond them, ending up with 4:15:XX.

The key point I would emphasize from Matt and Chris' posts is: when trying to project IM marathon time, do not use standalone times, or 5K speed. It's a totally different race, and needs totally different training and pacing strategies. Better to go with the VDOT and race execution model EN has perfected.

Chris G

Just another thought.  When is your Open PR from?  If it was from last Fall then maybe you can have some gage of fitness from that.  If it was from years ago under different circumstances it is really not worth much.  Marathon's are not like 5k's where you can run one every weekend, at least I can't.

FWIW I plan set a new marathon PR this summer in lake placid.  Luckily I have not run an open marathon since 2006 back when I was a lot slower.  That should help.

gilliatt

You've got some great feedback here from some really smart and fast folks. I can only add to the suckitupatude thing, sometimes this means actually slowing down like 10-15 seconds per mile when things get tough to sort of delay a spectacular blow up.
Here is an old chart that might sort of give you a range based on vdot

http://spreadsheets.google.com/ccc?key=pNU4T5RzFyJZOC62ii6zvEw&hl=en

JeremyBehler

Wow...thanks everyone. Very helpful. ALl the input from the WSM's here shows why you are WSMs!

@Craig - great tool....very in depth/geeky. Love it. BTW...also a Phish fan!

@Chris - my 3:10 was from November, so fairly recently. I was doing an EN like plan, but just joined EN in December.

I've been thinking that 3:45ish is a realistic goal which seems to be the case if I execute well.

mgraffeo

Jeremy, maybe the best way to think about it is that a time goal for the marathon is counter-productive, unless you've got previous experience and data to work off of. The best you can do is to drive your Vdot as high as possible, follow the plan nailing the runs, and then execute like crazy. Setting goals like running sub 3:xx tends to lead to dumb decisions in training and racing that lead to injury or walking...

And Chris, I had the same goal last year (mary PR inside an IM). Had the training not been derailed the way it was, I was totally convinced I was going to do it. Now, I've gotta run an open mary this year...

JeremyBehler

@Mike. I hear you. And while I understand/agree in principle that it's potentially counter productive the goal seeker in me is looking to establish something to shoot for. This will get refined as I get RRs under my belt, etc but gives me something to shoot for and motivate me during training. I know how important execution is, and would not sacrifice a solid race just to hit a split on the bike, run, etc.

My goal that keeps me motivated is to be sub 11 hours and I've been doing the math to see how this could potentially play out. I hear the caveats loud and clear, and certainly value the input from everyone hear given your experiences.

mgraffeo

The other thing that really goes under the radar on this is the bike. The better/stronger you are on the bike, the faster you'll be off it and on to the run. Hard to understate the benefit of being a strong biker on the IM run. Not overachieving on the bike, but having done the work to drive FTP up there.

ghernand

jeremy:

i have nothing to add other than my times at IMAZ 2010 and how i ran, since more experienced people have covered all the relevant formulas strategies, etc.   this is the race you are doing, right?

overall time 11:19:02;

run: 3:48:17 and my Vdot was a 52 going into the race based on a 13.1  four weeks out from the race in 1:27:33, that was hillier than IMAZ.;

bike: 6:01:33; but i screwed it up and went really low with the watts (142NP; FTP232)) due to not enough practice cycling and rain and cold;

swim: 1:20:34; oh well.

i do not know if i ran slower or faster than the predicted time based on the spreadsheet, but you can plug the numbers in if you like.

i walked 30 steps at each aid station except the last 2 on the final loop.  i did negative split, i think. 

i definitely did not enter the dark place during the run, but i plan to at IMCdA and i am faster now, although my current vdot is based on 5km and not a 13.1, so keep that in mind. 

what i did have, however, was prior knowledge of the course (i.e raced there 3 other times) and my legs were not wasted from the bike.  i caught a friend of mine who had a 35minute lead on me coming off the bike and i put 5 minutes on top of that. 

good luck!  gh

JeremyBehler

Thanks Gilberto. Looks like your run was pretty much in line with the calculator. Helpful real life example. Btw, I see in your sig that you've had a nice bump in your VDOT! 59 is pretty incredible.

Carrie Chavez

In my 13 IM's I tend to average about 40-45 minutes slower than stand alone marathon. In 2000 I ran 3:08 marathon, then 3:13 Boston 2001. Went to LP in July and ran at or under 4 hours. Maybe 3:58, can't remember. Not many folks are in the 3's. My husband has run 3:22 in Hawaii when he was a very fast runner. Like a 33-34 minute 10K runner. So to some it was under his potential but to him it was AWESOME. IM is a totally different beast. The charts folks have given are a better choice to follow. You are really shooting for z1 plus 30 seconds for first 6 and then z1 for the rest. SO hard to do.

I tried this pacing at IMSG last year until we realized the course was way too hilly and steep. I had to run perceived exertion and ran 3:58!!! Smoking fast for that course! ( as far as I am concerned, ha!!)