Estimating IM run time

kingQuez

19 weeks out from my first IM and I figure its time to get some ballpark estimates for splits, to be refined over the next couple of months. I've a reasonable idea of my swim time, can make an educated guess at the bike split but any attempt at estimating the run is a work of fiction. How long do your brick sessions need to be before you can come up with a reasonable guess at how well your legs with handle the run? I've just been taking my regular marathon time and adding an hour and a half (for no reason but that it will be slower than my regular marathon!). Where's mcmillan for triathlons!

Izoard

Hi KQ,

I think you are being a little conservative in your times there...

Have only 1 IM to go on, but I did 3.48 in Connemara in Apr 10, and did a 4.07 IM CH marathon in Jul 10 (12.07 total).
Even then, I could have easily gone sub-4, but I only realised too late, that my strategy of "walking the aid stations", was waaay too conservative, given that the IM marathons are one long aid station!

mloc123

What's your easy pace off the bike at the minute?

kingQuez

mloc123 wrote: »

What's your easy pace off the bike at the minute?

Hard to know really; long bike is only at 100k, and the run off is only long enough for legs to start to feel a bit more normal so I usually aim at 6min/km to avoid going too fast/slow.

mloc123

Okay, are you training based on HR? If so what is your easy range? for me its capped at 161... If I was estimating an IM split at the moment I would base it on the pace I hold while running easy off my long bike... even if the long bike is currently only 3hrs or whatever.

I am not training for an IM tho and this is just me... I'm sure some of the proper IM'ers will have more info

griffin100

I'm not a proper IM'er by any means but my 2c.....

My IM time last August was 4.42 off a long tough bike. I did DCM a couple of months later in 3.52. Allowing for the fact that my IM marathon was only 25 miles thats roughly an hour in the difference. These were my first and second marathons so it was all quite new.

Its not the pace that you can set running off the bike that dictates your run time, you'll soon loose the jelly leg feeling, its the level of fatgue you have after being in the saddle for a long time and how well you've fuelled up. These will dictate your run time more than how your legs feel for the first few minutes.

shotgunmcos

hmm the enigma of it The only real way to know is to have done an IM and learn from that. Besides that as mloc suggested all you can do is guage it from your most realistic transition run off your most realistic long bike.

I've been running comfortably off every bike over the winter but then most recently fell apart 3km after an underfeulled long bike

From the articles I've read you cannot use your open marathon time as an estimate but rather your easy pace off the bike. That said, if you are in good nick, pace the swim and especially the bike well, get your nutrition right and generally everything works to a tee, you could come within 20% of your standalone marathon time.

Granted you may have done a brick in training feeling great for 1-1.5hrs off the bike, but on the day its more about how little you slow down...

zico10

As a rough guide you can expect it to take a half hour longer than your marathon PB. 10 minutes because you've justed biked 180km, 10 minutes because you wouldn't have done the same training you would have done for a regular marathon and another reason was given to me for the final 10 minutes. I forget where the other 10 minutes comes from, but I remember it making sense when I was told.
An hour and a half is way too much. Don't blitz the bike and make sure you take fuel on board throughout the race. If you remember those two things you should be fine.

Notwitch

I think the Endurance Nation guys recommend using Daniels vdot calculator from a 5k / 10k race pre IM specific phase and then targeting your 'E Pace' off that - that seems to line up with their philosophy generally.

kingQuez

Great to see the consensus, I guess some mystery will add excitement over the next few months as I figure it out

I hadnt come across the daniels vdot calculator before; has anyone here used it and had good results from working at the suggested paces? Its got quite an optimistic range of predictions for me, although perhaps thats because some of the training paces are pretty evil looking :pac:

tunney

mloc123 wrote: »

What's your easy pace off the bike at the minute?

Not as applicable as you would think.

shotgunmcos wrote: »

hmm the enigma of it The only real way to know is to have done an IM and learn from that. Besides that as mloc suggested all you can do is guage it from your most realistic transition run off your most realistic long bike.

I've been running comfortably off every bike over the winter but then most recently fell apart 3km after an underfeulled long bike

From the articles I've read you cannot use your open marathon time as an estimate but rather your easy pace off the bike. That said, if you are in good nick, pace the swim and especially the bike well, get your nutrition right and generally everything works to a tee, you could come within 20% of your standalone marathon time.

Granted you may have done a brick in training feeling great for 1-1.5hrs off the bike, but on the day its more about how little you slow down...

Why off the bike?

zico10 wrote: »

As a rough guide you can expect it to take a half hour longer than your marathon PB. 10 minutes because you've justed biked 180km, 10 minutes because you wouldn't have done the same training you would have done for a regular marathon and another reason was given to me for the final 10 minutes. I forget where the other 10 minutes comes from, but I remember it making sense when I was told.
An hour and a half is way too much. Don't blitz the bike and make sure you take fuel on board throughout the race. If you remember those two things you should be fine.

Emmmmm sounds suspect

tunney

kingQuez wrote: »

19 weeks out from my first IM and I figure its time to get some ballpark estimates for splits, to be refined over the next couple of months. I've a reasonable idea of my swim time, can make an educated guess at the bike split but any attempt at estimating the run is a work of fiction. How long do your brick sessions need to be before you can come up with a reasonable guess at how well your legs with handle the run? I've just been taking my regular marathon time and adding an hour and a half (for no reason but that it will be slower than my regular marathon!). Where's mcmillan for triathlons!

At best your IM pace will be your long easy run pace. By this I mean the pace you hold consistently while running easy for three hours. Think middle of easy HRs.

However a number of factors influence this:
1) Biking /fueling : People will say "ohhhh I didn't fuel right thats why I couldn't run the whole thing", generally thats wrong. They rode too hard. Your muscles and liver store a set amount of fuel. You can absorb another (personal) upper limit amount of fuel over the course of the IM. The sum of these two is the total amount of fuel as glycogen/glucose that you have available REGARDLESS of how much you eat. Everyone has a wattage figure that when they ride harder than that their energy needs are being met by more CHO than they can take in and their stores and they are guaranteed to walk. So pace well, pace smart.
2) Durability: at some stage your quads will shut down. When that happens is important. If your legs are robust enough it will happen at 48km and happy days. If they are not then "oops" you're ****ed at 20km. This can be aided by training and the way you train and the sessions you do.

In short, your best case is your long easy pace and its unlikely you'll hold that for everything but adapt and react to the situation and see how it goes. I'd run by PE for first 5km and then work from there and remember the water is in cups!!!

zico10

tunney wrote: »

Emmmmm sounds suspect

I did say it was only a rough guide.
I heard it from a Kona qualifier, who is not inclined to waffle. I'd say it's also true enough of most of the Irish who perform at that level. My guess would be the main reason it does't work out for most starters is because they probably mess up the bike.
At the very top level, would Craig Alexander and Chrissie Wellington not be running roughly 2.18 and 2.33 marathons respectively, if they were to go about running marathons the way most triathletes in Ireland do?

Reville

i've done 6 IM's now and 5 marathons and reckon the 30 minutes is bang on.
in 2010 i had 2:47 and 2:53 in marathons and 3:17 and 3:18 IM splits.

for most guys i know that race IM regularly this pretty much holds true, with one or 2 exceptions.

key though is

• pacing on the bike, plenty people smash themselves for sub 5 hour bike to end up with >4 hour run. i try to stick to 145HR on bike cause this works for me. still to break that 5 hour mark on bike though.
• pacing at start of run. coming out of T2 can sometimes feel great, vital to stick to pacing strategy.
• nutrition - get carbs, salt and fluid in at every aid station, and if hot ice in cap and down shorts.
• other issues - i always have slow T2 cause Vaseline up and suncream heavily. while i need to improve this i think 30 seconds lost there can save alot of time later when discomfort sets in.
• if a hilly course dont smash yourself too much on the uphills.

hope this helps a bit.

Iron Enthusiast

I think 30 mins probably sounds about right, although it all depends how hard you push the bike. Go too hard you might blow up on the run. You'll get to know your own limits better over the next few months. Enjoy and good luck!

tunney

Reville wrote: »

i've done 6 IM's now and 5 marathons and reckon the 30 minutes is bang on.
in 2010 i had 2:47 and 2:53 in marathons and 3:17 and 3:18 IM splits.

for most guys i know that race IM regularly this pretty much holds true, with one or 2 exceptions.

key though is

• pacing on the bike, plenty people smash themselves for sub 5 hour bike to end up with >4 hour run. i try to stick to 145HR on bike cause this works for me. still to break that 5 hour mark on bike though.
• pacing at start of run. coming out of T2 can sometimes feel great, vital to stick to pacing strategy.
• nutrition - get carbs, salt and fluid in at every aid station, and if hot ice in cap and down shorts.
• other issues - i always have slow T2 cause Vaseline up and suncream heavily. while i need to improve this i think 30 seconds lost there can save alot of time later when discomfort sets in.
• if a hilly course dont smash yourself too much on the uphills.

hope this helps a bit.

Welcome to Boards.ie Mr. Reville.

The man knows his stuff and I defer to his opinion.

He neglected to mention his last IM was 9:48 in Kona

pgibbo

tunney wrote: »

Welcome to Boards.ie Mr. Reville.

The man knows his stuff and I defer to his opinion.

He neglected to mention his last IM was 9:48 in Kona

Nice splits too.....another example of not having to swim sub 60 to go sub 10 (01:05:06, 05:15:46, 03:19:17, 09:47:59) :cool:

shotgunmcos

pgibbo wrote: »

Nice splits too.....another example of not having to swim sub 60 to go sub 10 (01:05:06, 05:15:46, 03:19:17, 09:47:59) :cool:

Yeah you don't need to be a sub60 swimmer but bases on reville and zico10 you would want to be a 2:50 marathon runner :rolleyes:

pgibbo

shotgunmcos wrote: »

Yeah you don't need to be a sub60 swimmer but bases on reville and zico10 you would want to be a 2:50 marathon runner :rolleyes:

Don't forgot the animal bike splits too.......No bother to you though!

Reville

Sub 60 swim is hard to get in Kona unless you very good swimmer. This despite Kona swim being perfect conditions, straight out to turn buoy at 1.9k and back, with huge buoys for sighting and super clear water, and it’s a washing machine for getting onto fast feet.
But it’s an accurate 3.8k and non-wetsuit plus some tidal current. Perhaps some other IM swims a bit short.
Us Irish didn’t have comparatively fast swims there in 2010, splits ranging from 1:05 to 1:25 I think. But we all ran under 3:20, and the other lads had some blistering bike times, Liam D in particular charged thru the field after sluggish swim!

Anyhow hopefully there’ll be a good Irish representation at Kona again in 2011, and we’ll see a sub 9 result somewhere.

zico10

Reville wrote: »

[*]pacing on the bike, plenty people smash themselves for sub 5 hour bike to end up with >4 hour run. i try to stick to 145HR on bike cause this works for me. still to break that 5 hour mark on bike though.

How many other people who have raced ironman used HR as a guide? I'm aware of its usefulness, but do you not find it overly distracting? Would your level of perceived effort not be as reliable a guide?
Ultimate respect for what Reville has achieved and I acknowledge he says it's what works for him, but do the pros use it?
I'm only asking about racing specifically, not training.

tunney

PRO racing and AG racing are not comparable.

AGers are generally racing to a time goal and and operate accordingly.

PROs are racing each other. If someone goes full gas at a point where breaks need to be covered does it matter what your HR/PE/Power says? No - the break must be covered

Just because the PROs don't treat it as gospel or your local Kona qualifier doesn't use it doesn't mean that that is the approach to take.

Doesn't mind it is either but most would advise it.

shotgunmcos

So which is better to indicate a possible IM run pace, your long run at x heart rate, or the run off a long bike at x heart rate? Assuming 3hrs vs 1hr runs respectively

tunney

Straight marathon +30 minutes. Shessssh. Do you not pay attention?


(personally the pace I think I'd run and is the pace I hold just running easy - 3:10 last year but hadn't counted on cups)

pgibbo

tunney wrote: »

Straight marathon +30 minutes. Shessssh. Do you not pay attention?


(personally the pace I think I'd run and is the pace I hold just running easy - 3:10 last year but hadn't counted on cups)

And if you have never run a marathon or have a very out of date marathon time? Would you use one of the 2 methods MCOS suggested or take a McMillan marathon time based on a recent half or 10mile race?

shotgunmcos

tunney wrote: »

Straight marathon +30 minutes. Shessssh. Do you not pay attention?


(personally the pace I think I'd run and is the pace I hold just running easy - 3:10 last year but hadn't counted on cups)

As pgibbo said, if you have not run a straight marathon? My own straight marathon time is from 2008 so hardly useful

kennyb3

pgibbo wrote: »

And if you have never run a marathon or have a very out of date marathon time? Would you use one of the 2 methods MCOS suggested or take a McMillan marathon time based on a recent half or 10mile race?

I think what Tunney is saying whats the point spending all the time estimating it off 10m times? An estimate is a guess - just pluck a figure out of the sky you think you might run. Even if you have some magic formula it wont hold true for everyone.

zico10

tunney wrote: »

PRO racing and AG racing are not comparable.

AGers are generally racing to a time goal and and operate accordingly.

PROs are racing each other. If someone goes full gas at a point where breaks need to be covered does it matter what your HR/PE/Power says? No - the break must be covered

Just because the PROs don't treat it as gospel or your local Kona qualifier doesn't use it doesn't mean that that is the approach to take.

Doesn't mind it is either but most would advise it.

Appreciate all that, but have you ever raced solely based on PE? Do you not think you'd know your capabilities well enough at this stage, to know if you're pushing too hard or taking it too handy, whatever the case may be?

Getting back to the pros, Chrissie Wellington, who is so far ahead of anyone else, she doesn't need to worry about breaks. Does anyone know if she races off HR? Theoretically and in practise, she could just evenly pace herself from start to finish and still win, set course records, etc.

As you say your local Kona qualifier mightn't use. Why is there any reason why what works for one, shouldn't work for the other?

jcunniffe

If it's your first IM then, yes, you can use estimates based on brick paces, long run HRs, MacMillan + 30mins, etc.

However, it doesn't really matter once you get on the tarmac out of T2. The most important thing will be able to adapt your run pace as you go based on perceived exertion and other body signs.

HRs may well be funny depending on what state your body is in and you may not even be able to get your heart rate up to your 'HR cap' towards the end of the race! In any case if this is your first IM, you will have limited data from training and racing on how your HR responds over this duration and fatigue level. (How much data do you think Chrissie W or Macca have on how their bodies perform at their "IM run pace" after 3.8km swim/180km bike? How much do you have?)

If you set off out of T2 at some pre-planned pace and it's too fast then you are in for a long day at the office.

Everyone knows that IM has a great fireworks show but it's not the midnight finish line show. It's watching runners who stuck to 'pre-race plan' pace until they blew up all over the road between 10 and 35km into the marathon.

You encounter the gun who went past you at 45kph 6hours ago who is now walking 10min/km at 21km and is trying to stuff pretzels and coke into an engine that died an hour ago.

So when you're picking your run pace for your first IM you can decide to be conservative and adapt up the pace if the body feels good or you can decide that you're feeling lucky and try to hit a pre-calculated MacMillan + 30mins or whatever. You gotta ask yourself one question though. It's your first IM and do you feel lucky?

Enjoy the fireworks .....

J

shotgunmcos

LOL JC, you forgot 'punk' at the end of that question.

tunney

My point was PE is very much affected by ego. Power and HR caps are not.

I think PE, HR and power/pace are the way to go. A few different metrics to perhaps help postpone the wheels coming off.

Reville

perceived effort can be misleading especially if 1st IM.
IM run can feel great at some stages and shocking later if mis-paced or dehydrated / cramping. sticking in right heart rate zone should help avoid or at least delay this.

though HR alone can be flawed too with spikes or faulty readings. combination of HR and PE prob works best.

personally i run marathon at around 160 av HR, but hold back to 145-150 for IM run.

zico10

tunney wrote: »

My point was PE is very much affected by ego. Power and HR caps are not.

I think PE, HR and power/pace are the way to go. A few different metrics to perhaps help postpone the wheels coming off.

Reville wrote: »

perceived effort can be misleading especially if 1st IM.
IM run can feel great at some stages and shocking later if mis-paced or dehydrated / cramping. sticking in right heart rate zone should help avoid or at least delay this.

though HR alone can be flawed too with spikes or faulty readings. combination of HR and PE prob works best.

personally i run marathon at around 160 av HR, but hold back to 145-150 for IM run.

Thanks for responses, I intend to educate myself on all this. But I still think I'll stick to PE for next time I race ironman. Might be a costly lesson for me someday, but I trust myself to pace things right.

tunney

The run is easy to pace, its pacing an aggressive bike split thats tricky.

OT but did that sub ten thread ever get started? Can see any sign of it?

bryangiggsy

zico10 wrote: »

How many other people who have raced ironman used HR as a guide? I'm aware of its usefulness, but do you not find it overly distracting? Would your level of perceived effort not be as reliable a guide?
Ultimate respect for what Reville has achieved and I acknowledge he says it's what works for him, but do the pros use it?
I'm only asking about racing specifically, not training.

I used Heart rates for my 2nd Ironman in Frankfurt last year. I was skeptical at first but my coach from QT2 systems convinced me to give it a go. He estimated with my numbers that to run well of the bike i was to keep my HR around 135 for the bike. I stuck to the plan along with the nurtrition (nb*) and as a result passed over 700-800 people on the marathon. The year before in LP i did not use HR's and instead went with my instict.suffering on the 2nd lap of the bike and absolute carnage on the run.
For the run in Frankfurt i stuck not to hr but to pace per km and maintained the same pace for the marathon without stopping once.
What worked for me may not work for you and vice versa but that was my experience. Best of luck.

kingQuez

tunney wrote: »

The run is easy to pace, its pacing an aggressive bike split thats tricky.

OT but did that sub ten thread ever get started? Can see any sign of it?

yep,
http://www.boards.ie/vbulletin/showthread.php?t=2056182837