General Discussion Triathlon Talk » Using a HM time to predict a Marathon time Rss Feed  
Moderators: k9car363, alicefoeller Reply
2010-10-12 9:01 PM

User image

Subject: Using a HM time to predict a Marathon time

There is a very "generic" formula of HM x 2 + 10 minutes gives you your estimated marathon time.  I know it's not that simple, and you have to put in the miles during training for that formula to be even close...but...what do you use as your best marathon predictor.

Last year I used a half marathon (which was run as a B race...small taper and 95% effort) 5 weeks before my marathon.  I ran 1:55:59, so given that I didn't go all out...I figured I could go sub 4 in my marathon 5 weeks later...even though the formula predicts 4:02.

I ended up running 3:58:32 with fairly even splits...so it was a pretty good predictor...but I was a total train wreck trying to hold that pace the last 4 miles.  And I didn't enjoy the experience at all other than making my goal.

This year I want to beat my time...but enjoy the race as well.  I'd like to go sub 3:55.  I'll be doing the same HM five weeks out...so I'd like to know if 3:55 is possible without killing myself.  So given that I'll be doing the HM as a B race...what type of time do you think would indicate that? 

Right now, my plan is to try and run 1:52.  If I can do that, I'll shoot for 3:55 (since the predictor calculates 3:54...and I'd be running 1 minute slower than the predictor...instead of 3.5 minutes faster than the predictor like I did last year).  If I run 1:56 again, I'm shooting for 4:05...and if I feel good, I'll try to negative split for sub 4.

Thoughts?  Opinions?  Other calculators you've used?

FYI, this year and last, I'm running about 40-50 mpw during the heart of the training program.  The only difference with this year is that my long runs are at about 10:00-10:20 compared to last year at 10:20-10:40.  I also feel 2x better after my long runs this year...where last year my coworkers could tell by how I walked if I had done a long run the day before.



Edited by tri808 2010-10-12 9:04 PM


2010-10-12 9:25 PM
in reply to: #3148604

User image

Resident Curmudgeon
25290
50005000500050005000100100252525
The Road Back
Gold member
Subject: RE: Using a HM time to predict a Marathon time
McMillan says you need a 1:51:26 HM to have an equivalent 3:55 full
2010-10-12 9:38 PM
in reply to: #3148639

User image

Subject: RE: Using a HM time to predict a Marathon time
the bear - 2010-10-12 5:25 PM McMillan says you need a 1:51:26 HM to have an equivalent 3:55 full


Good to know.

If I plug my 1:55:59 time from last year (again...B race effort) into there...I get 4:04:37...which I beat by 6 minutes.

So I assume a B race effort of ~1:52 should predict about 3:50...which should mean 3:55 is a goal I can get without killing myself like last year.
2010-10-12 9:41 PM
in reply to: #3148639

User image

New Haven, CT
Subject: RE: Using a HM time to predict a Marathon time

It all depends.  I ran a 1:47 20K labor day and it felt easy (B effort race, goal was to run mary pace for 12 miles, I ran 8:40s and basically eased off the last 3 miles).  I thought I would have a legit shot at sub 4 for my marathon last week.  Not even close 4:36.  Everything went wrong on race day.  Best of luck.



Edited by jsklarz 2010-10-12 9:42 PM
2010-10-12 9:49 PM
in reply to: #3148660

User image

Subject: RE: Using a HM time to predict a Marathon time
jsklarz - 2010-10-12 5:41 PM

It all depends.  I ran a 1:47 20K labor day and it felt easy (B effort race, goal was to run mary pace for 12 miles, I ran 8:40s and basically eased off the last 3 miles).  I thought I would have a legit shot at sub 4 for my marathon last week.  Not even close 4:36.  Everything went wrong on race day.  Best of luck.



How did your LRs during training go?  My assumption for any type of calculator is that I would need to hit my weekly mileage and LRs consistantly.  The other assumption is that the weather isn't out of the norm on race day.

Edited by tri808 2010-10-12 9:50 PM
2010-10-13 8:38 AM
in reply to: #3148667

User image

Champion
7233
5000200010010025
Subject: RE: Using a HM time to predict a Marathon time
Something else to think about (i have no idea on time goals, i've seen people that can hammer out 16min 5ks not run under 1:30 for a half), but do you want to PR or have fun during the race? Not that these have to be one or the other, but racing hard and having "fun" are not always the same thing.

Now if you mean fun in being able to push hard the whole way and race vs complete it, totally agree.


Assuming you pace well it seems like people that are well trained are around half maryx2 + 10 min or so give or take (sort of what you mentioned).

Would not say its hard and fast, but a good place to start.


2010-10-13 8:51 AM
in reply to: #3148604


1072
10002525
Subject: RE: Using a HM time to predict a Marathon time
Personal experience:I ran 1:35 HM at a hard effort (for me) and 12 weeks later ran a 3:41 marathon. I was planning on a 3:30 marathon time. I was on pace until the 22 mile mark, but it was a struggle after that and I faded to the 3:41. My Long runs had gone very well leading up to the taper before the marathon. I was doing 40 - 45 miles per week

By your calculation I should have been done a 3:20. A year earlier I had done a 3:47 marathon with a negative split and felt strong all the way through the end. I guess I was not ready for that little increase in pace even though I thought I was.

Good Luck on making your goal
2010-10-13 9:00 AM
in reply to: #3148667

User image

New Haven, CT
Subject: RE: Using a HM time to predict a Marathon time
tri808 - 2010-10-12 10:49 PM
jsklarz - 2010-10-12 5:41 PM

It all depends.  I ran a 1:47 20K labor day and it felt easy (B effort race, goal was to run mary pace for 12 miles, I ran 8:40s and basically eased off the last 3 miles).  I thought I would have a legit shot at sub 4 for my marathon last week.  Not even close 4:36.  Everything went wrong on race day.  Best of luck.



How did your LRs during training go?  My assumption for any type of calculator is that I would need to hit my weekly mileage and LRs consistantly.  The other assumption is that the weather isn't out of the norm on race day.


20 miler included 5000 feet of climbing and I was alone the whole time and was very tough.  22 miler only had 3800 feet of climbing and I felt fine (10 minute pace, which was per plan, 1 minute slower than race pace.)  My last tempo run was 4 miles at race pace, which I hit on a hilly route (1800 feet of climbing, 800 in the last mile).  Weather was perfect on race day, I was just off and, I believe, undertrained.
2010-10-13 11:07 AM
in reply to: #3148604

User image

Master
1430
100010010010010025
Calgary, AB
Silver member
Subject: RE: Using a HM time to predict a Marathon time
Mcmillan is known to be very agressive for the full marathon time, compared to the 10/HM/5k etc, even assuming volume targets are hit. So take it with a grain of salt.
2010-10-13 11:16 AM
in reply to: #3149207

User image

Subject: RE: Using a HM time to predict a Marathon time
newbz - 2010-10-13 4:38 AM Something else to think about (i have no idea on time goals, i've seen people that can hammer out 16min 5ks not run under 1:30 for a half), but do you want to PR or have fun during the race? Not that these have to be one or the other, but racing hard and having "fun" are not always the same thing. Now if you mean fun in being able to push hard the whole way and race vs complete it, totally agree. Assuming you pace well it seems like people that are well trained are around half maryx2 + 10 min or so give or take (sort of what you mentioned). Would not say its hard and fast, but a good place to start.


That's the idea...go hard...challenge myself...but not make the last 4 miles a life changing experience.  I expect it to hurt...I expect it to be tough...but I want to at least be able to crack a smile from time to time.  That wasn't the case last year.

2010-10-13 11:19 AM
in reply to: #3149234

User image

Subject: RE: Using a HM time to predict a Marathon time
browncd - 2010-10-13 4:51 AM Personal experience:I ran 1:35 HM at a hard effort (for me) and 12 weeks later ran a 3:41 marathon. I was planning on a 3:30 marathon time. I was on pace until the 22 mile mark, but it was a struggle after that and I faded to the 3:41. My Long runs had gone very well leading up to the taper before the marathon. I was doing 40 - 45 miles per week By your calculation I should have been done a 3:20. A year earlier I had done a 3:47 marathon with a negative split and felt strong all the way through the end. I guess I was not ready for that little increase in pace even though I thought I was. Good Luck on making your goal


Thanks for your input.

If I had a HM time of 1:35...my interpretation of the formula would be that 3:20 was possible if I was putting in 60+ miles per week during trainig.  I'm not a naturally gifted runner...so I would have to put in more miles than others for the formula to hold true.  As it is...I'm thinking 40-45 is borderline low for me with my current goal...but it's all I can handle without getting injured at the current time.


2010-10-13 11:27 AM
in reply to: #3148604


16

Subject: RE: Using a HM time to predict a Marathon time
Do you train using HR? If so, which zones are you in for the HM and M?
2010-10-13 11:29 AM
in reply to: #3148639

User image

Sensei
Sin City
Subject: RE: Using a HM time to predict a Marathon time
the bear - 2010-10-12 7:25 PM McMillan says you need a 1:51:26 HM to have an equivalent 3:55 full


This is what I was going to suggest.  McMillan.  I find it pretty accurate, both with pace and HR estimates.

There is a good triathlon calculator as well, but I need to search for it.
2010-10-13 11:54 AM
in reply to: #3149714

User image

Subject: RE: Using a HM time to predict a Marathon time
gruntwork - 2010-10-13 7:27 AM Do you train using HR? If so, which zones are you in for the HM and M?


I used to...but my HRM doesn't seem to work anymore when I run.  It constantly reads numbers in the 170-190 range even when jogging.  When it did work, I was in the 130-150 range during most of my training depending on what type of run it was.
2010-10-13 12:15 PM
in reply to: #3148604

User image

Extreme Veteran
590
500252525
Seattle
Subject: RE: Using a HM time to predict a Marathon time
I think the + 10 min part is suspect.  Those 10 minutes can be 8% of total time (WR runner) to just 3% of total time (5+ hours).  So that + amount is going to vary.

In general, double the HM time + extra 10% might be more realistic.  So a 1:53 HM would give 3:57 Marathon time.

2010-10-13 12:57 PM
in reply to: #3149838

User image

Subject: RE: Using a HM time to predict a Marathon time
Lilac J - 2010-10-13 8:15 AM I think the + 10 min part is suspect.  Those 10 minutes can be 8% of total time (WR runner) to just 3% of total time (5+ hours).  So that + amount is going to vary.

In general, double the HM time + extra 10% might be more realistic.  So a 1:53 HM would give 3:57 Marathon time.



Very good point.

Edited by tri808 2010-10-13 12:58 PM


2010-10-13 1:56 PM
in reply to: #3149695


1072
10002525
Subject: RE: Using a HM time to predict a Marathon time
tri808 - 2010-10-13 11:19 AM

browncd - 2010-10-13 4:51 AM Personal experience:I ran 1:35 HM at a hard effort (for me) and 12 weeks later ran a 3:41 marathon. I was planning on a 3:30 marathon time. I was on pace until the 22 mile mark, but it was a struggle after that and I faded to the 3:41. My Long runs had gone very well leading up to the taper before the marathon. I was doing 40 - 45 miles per week By your calculation I should have been done a 3:20. A year earlier I had done a 3:47 marathon with a negative split and felt strong all the way through the end. I guess I was not ready for that little increase in pace even though I thought I was. Good Luck on making your goal


Thanks for your input.

If I had a HM time of 1:35...my interpretation of the formula would be that 3:20 was possible if I was putting in 60+ miles per week during trainig.  I'm not a naturally gifted runner...so I would have to put in more miles than others for the formula to hold true.  As it is...I'm thinking 40-45 is borderline low for me with my current goal...but it's all I can handle without getting injured at the current time.


By no stretch am I a "naturally gifted runner" . It took me almost 2 years to gradually build up to running 40 - 44 miles per week. And another year to get my time for the HM down in that range.
I started out running 3 miles around 9:00 min per mile 5 times a week. I followed the 10% increase rule with every 4th week a recovery week where I cut back up to 40%. I ran a few 5K and 10K races at the end of the recovery week during the spring, summer and fall if I could find one in the area.

In the second year I gradually built up my mileage to run a marathon. I was aiming for under 4 hours and came in at 3:47
It wasn't until the third year that I added any "speed" work. I did a tempo run(4miles) once a week at 10K pace and later added 4 - 1 mile repeats at 5K pace. The long runs only went up 1-2 miles each month. I stayed injury free during this time. Part of the reason I took so long to build up my mileage was because the first time I tried to go from the couch to a marathon in 6 months. It was a mess. I ended up with a stress fracture and PF. Along with the injuries I was burnt out so I quit running for 6 months before I started again.


Edited by browncd 2010-10-13 1:59 PM
2010-10-13 7:16 PM
in reply to: #3148604

User image

Member
319
100100100
Seattle, WA
Subject: RE: Using a HM time to predict a Marathon time
Wow! I am amazed! That HMx2 + 10% formula was EXACT for my most recent HM/marathon prediction. HM in June: 1:39:28 and marathon on Sunday: 3:38:01. Agreed that McMillan, etc. Were all too aggressive. They all predicted I would run about 10 minutes faster, and I gave it everything I had both in training and on race day, with negative splits. Had an awesome time out there though.
2010-10-14 12:42 PM
in reply to: #3148604

User image

Master
1882
1000500100100100252525
Chandler, Arizona
Subject: RE: Using a HM time to predict a Marathon time

As a point of reference, last October I had a 1:50:27 run split in my first HIM. The following Jan, I ran a 3:41:15 marathon.

2010-10-14 2:05 PM
in reply to: #3148604

User image

Elite
5316
5000100100100
Alturas, California
Subject: RE: Using a HM time to predict a Marathon time

My first mary was 3:48:xx ish and my send mary was 3:19:xx.  You can drop the time, but you need to 1) have a decent base, 2) put in the miles and 3) do some intensity work to get faster (I built to something like 12 x 800 repeats at race pace with 800 fast 800 slower).  Luck on your journey.  It is hard work getting faster, rather than just getting the distances in.   

New Thread
General Discussion Triathlon Talk » Using a HM time to predict a Marathon time Rss Feed