Half marathon as predictor of marathon time

neilc

HM = 112; M = 290
HM x2 = 224
M - (HMx2) = 66
66/112 = 59%

I'm putting my results down to not been able to do any of my scheduled 3 week taper at all due to injury. My 20 mile long run which was just over 4 hr pace, was the last run I did before the marathon. Saying all that I'm over the moon having completed my first marathon.
Neil

Racing Flat

tunney wrote: »

What calculators could tell you is. If you trained for a half and ran X, and if you trained for a marathon you could run Y. Doesn't mean that if you went out and ran you would. Means you could.

Exactly. In fairness, most of the calculators say 'as long as you race on a similar course in similar conditions and do teh appropriate training for the distance to be predicted'. Whereas it seems clear enough form here that for whatever reason, that does not appear to be the case, most typical boards pundits seem a fair bit out from what would be predicted.

So in future when someone asks me what they should aim for based on a 2.00 half, I'll lean towards 4.45, rather than 4.15-4.20...

christeb

HM = 93; M = 215
HM x2 = 186
M - (HMx2) = 29
29/93 = 31%

too high!

aero2k

HM 85
M 119
M-(2xHM) = 9
9/85 = 10.6 %

The HM course was a little tougher, and I wasn't 100% on the day - I think 83 min was a closer reflection on my ability which would make the result of the above calculation 15.5%.

shels4ever

Racing Flat wrote: »

Exactly. In fairness, most of the calculators say 'as long as you race on a similar course in similar conditions and do teh appropriate training for the distance to be predicted'. Whereas it seems clear enough form here that for whatever reason, that does not appear to be the case, most typical boards pundits seem a fair bit out from what would be predicted.

So in future when someone asks me what they should aim for based on a 2.00 half, I'll lean towards 4.45, rather than 4.15-4.20...

I'd agree with that too upto a point, Based on a 1:59 half i was going to try a sub 4 marathon ... which was never going to happen but i'm fairly sure I would have run a 4:20 with out much problem. The half mara was 8 week prior to the marathon on a harder course. Ok ended up injured maybe due to the target been too ambitious.


From the figures i see here it seems that the lower % seem to be from the more experienced runners , i'd say this is due to consistent training over years so both half mara and mara were at close to peak performance.

The newer marathon runners seem to suffer more, but will see a better % improvemnet over time. I think what i'm getting at is running a marathon is possible with a 16 week program but running a fast marathon is a sum of years of work. If your going to be 4+ hours on your feet the chances of things going wrong increase compared to the 2:30-3:00 gang.

shels4ever

aero2k wrote: »

HM 85
M 119
M-(2xHM) = 9
9/85 = 10.6 %

The HM course was a little tougher, and I wasn't 100% on the day - I think 83 min was a closer reflection on my ability which would make the result of the above calculation 15.5%.

Nice sub 2 horus marathon

aero2k

shels4ever wrote: »

Nice sub 2 horus marathon

Ah, how cruel of you to tread on my dreams - should have stopped by that laser vision stand at the expo. (119 looks a lot like 179 on my screen!) Sums were still good though...

smmoore79

HM 81
Mar 190
HM x 2 = 162
190-162 = 28
28/81 = 35%

Have no idea what this figure tells me .... room for improvement?

tunney

Racing Flat wrote: »

Exactly. In fairness, most of the calculators say 'as long as you race on a similar course in similar conditions and do teh appropriate training for the distance to be predicted'. Whereas it seems clear enough form here that for whatever reason, that does not appear to be the case, most typical boards pundits seem a fair bit out from what would be predicted.

So in future when someone asks me what they should aim for based on a 2.00 half, I'll lean towards 4.45, rather than 4.15-4.20...

All comes down to experience.

If hunnymonster was to say, "I will run 2:29 in a marathon based on the position of the moon and stars on the first day of tulips blooming this year" I'm going to believe her. Doesn't really matter what she is basing it on, she knows herself, her fitness, her form and what she could knock out.
If a newbie says "Well I ran 42:00 in my first 10km and based on macmillion I should run 3:39" I'm going to think more 4:15-4:45

tunney

shels4ever wrote: »

I'd agree with that too upto a point, Based on a 1:59 half i was going to try a sub 4 marathon ... which was never going to happen but i'm fairly sure I would have run a 4:20 with out much problem. The half mara was 8 week prior to the marathon on a harder course. Ok ended up injured maybe due to the target been too ambitious.


From the figures i see here it seems that the lower % seem to be from the more experienced runners , i'd say this is due to consistent training over years so both half mara and mara were at close to peak performance.

The newer marathon runners seem to suffer more, but will see a better % improvemnet over time. I think what i'm getting at is running a marathon is possible with a 16 week program but running a fast marathon is a sum of years of work. If your going to be 4+ hours on your feet the chances of things going wrong increase compared to the 2:30-3:00 gang.

If you are going to be 4+ hours on you're feet then the chance of something going wrong are increased because of a lack of fitness not because of time on feet. To be honest expected to go from zero to marathon with a 16 week programme is a bit of a joke and there is no way you can predicit anything. Getting to the start line is an achievement as I'd imagine a significant proportion get injuries due to demanding too much too soon from their bodies.

shels4ever

tunney wrote: »

If you are going to be 4+ hours on you're feet then the chance of something going wrong are increased because of a lack of fitness not because of time on feet. To be honest expected to go from zero to marathon with a 16 week programme is a bit of a joke and there is no way you can predicit anything. Getting to the start line is an achievement as I'd imagine a significant proportion get injuries due to demanding too much too soon from their bodies.

Yep thats exactly what I mean,

Jenfer

HM -117
M- 244
HM x 2- 234
244- 234 = 10
10/117 = 8.5%

think i could have knocked a few min off HM though- started too far back, went out a bit conservatively in hindsight.

Bobby04

HM - 97
M - 220
HM x 2 - 194
220 - 194 = 26
26/97 => 27%

The half I'd say was as good as it could have been in Sept, while for the full I slowed dramatically with the legs just giving up. Really thought I had 3:30 in me if everything had worked on the day, which would have been 16%. So even if things had gone ideally for me on the day, I'd have been nowhere near 10% rule of thumb!

kennyb3

another point has to be how soon into their schedule is the 10k or HM, if its in the first few weeks for example they may make big improvements off a low base. if the HM time is later on you can start adding 20% plus.

anyway like tunney points out its a futile exercise - there seems to be such a wide range. however it is still a very interesting thread and something i was thinking to myself teh day after the marathon

mrak

Good idea rf - last year:

Half 01:14:46
Full 02:37:37
Halfx2 02:29:32
Diff 00:08:05
% 10.81%

2004 one when just getting into running was:

Half 01:30:10
Full 03:20:40
Halfx2 03:00:20
Diff 00:20:20
% 22.55%

I'd guess that anyone with > about 15% probably hasn't trained enough to reach their potential (I know that was the case with me).

ike

mrak wrote: »

I'd guess that anyone with > about 15% probably hasn't trained enough to reach their potential (I know that was the case with me).

I'd definately agree with that would have got x=15% if I'd put in the effort for Berlin..

Art of Noise

HM: 109 mins
FM: 238 mins
HM x 2: 218 mins
Diff: 20 mins
20/109 = 18%

Peckham

Interesting thread, especially that even the best results from recent times here are coming out with c.15% variance.

However, as has been pointed out - a lot of marathon results are based on insufficient training. Also, marathons are going to expose more mistakes than a half marathon will.

For example, go out too fast in a half marathon, you'll probably hang on if your training is good. Go out too fast in a marathon, you're a goner regardless of how good you're training is. Similarly, putting a fast segment in a half is fine, not so in a marathon.

All things being equal, the 10% rule is probably accurate (doesn't it work fine for the elites?). The problem with us is that our collective racing experiences are littered with mistakes, but they only impact on our times over 26.2 miles.

psychozeb

HM; 98
M; 200
HMx2 196
200-196=4
4/98=3.92%


i'm a one speed guy.half marathon was in blarney with the killer hill.my best marathon so far was dublin 09 first half 1:40:10 second half 1:40:10 giving me my pb of 3:20:20.need to do speed work badly.

and for the record dublin 08 2nd half of marathon 1:40:13-consistent

hawkwing

HM; 106
M; 250
HMx2 212
250-212=38
38/106=36% :eek:

I certainly am not built for 26.2 miles

TFBubendorfer

Interesting formula.

HM = 85
FM = 185
HM x 2 = 170
185 - 170 = 15
15 / 85 = 17.6%

Would have needed 11% to get a sub-3 out of a 85 mins HM

Art of Noise

I've decided to bump this old thread with the Dublin Half Marathon and Marathon coming up.

Interestingly I did a half marathon and marathon (longford) recently and even with the faster times I still come out with the same % as two years ago. Shows its a consistent formula for ones performance imo.

HM: 87 mins
M: 190 mins
HM x 2: 174mins
190 - 174 = 16
16/87 = 18.3%

Itziger

Bump for the Sub 3 people. I'm not trying to depress anyone but every year we see some very ambitious predictions. Now as I said in the sub 3 thread, a really good training block of 12 to 16 weeks can override the Half time and make it less relevant.

As for the %. Here are mine (Although the Half was done after the Full!!) Half PB is 1.22 but I don't think I was in that shape pre marathon. I was more 1.23/24.

HM = 83x2 = 166
M = 179
179 - 166 = 13
13/83 = 15.66

Who's got the most impressive low %? Not surprisingly I'd say Krusty's numbers are fairly decent.

Itziger

Hadn't seen Psychozeb's 3.92!!!!!!!!!!!!!!

Then again, maybe that explains the handle someways.

RayCun

a thread from the vaults :pac:

Most recent marathon was 2014 -
Half: 83 (Dublin half)
Full: 176 (Dublin)
176 - 166 = 10
10/83 = 12%

earlier that year I ran

Half: 83 (Bohermeen)
Full: 179 (Limerick)
179 - 166 = 13
13/83 = 15%

First marathon was 2010 (Dublin half and full again)
Half: 108
Full: 238
238 - 216 = 22
22/108 = 20%


This thread covers similar ground

snailsong

Interesting thread, kinda telling me what I already know but don't want to accept...

2017 Half (Kinvara) 87
2017 Full (Rotterdam) 184
Full- 2 x hm....10
10/87= 11%

So 180/2.11=85.3 meaning at this rate I need 1:25:18 for my half in order to go sub 3. Latest was 1:26:42...Mehhh

average_runner

snailsong wrote: »

Interesting thread, kinda telling me what I already know but don't want to accept...

2017 Half (Kinvara) 87
2017 Full (Rotterdam) 184
Full- 2 x hm....10
10/87= 11%

So 180/2.11=85.3 meaning at this rate I need 1:25:18 for my half in order to go sub 3. Latest was 1:26:42...Mehhh

Unless its a very hilly course, you need to go under 123 to get the sub 3.

snailsong

average_runner wrote: »

snailsong wrote: »

Interesting thread, kinda telling me what I already know but don't want to accept...

2017 Half (Kinvara) 87
2017 Full (Rotterdam) 184
Full- 2 x hm....10
10/87= 11%

So 180/2.11=85.3 meaning at this rate I need 1:25:18 for my half in order to go sub 3. Latest was 1:26:42...Mehhh

Unless its a very hilly course, you need to go under 123 to get the sub 3.

So you're saying that in order to improve my marathon by 4 minutes I need to improve my half by 4 minutes?

Itziger

snailsong wrote: »

So you're saying that in order to improve my marathon by 4 minutes I need to improve my half by 4 minutes?

As you'll have seen and heard, it's not as simple as 1.23=2.59. I've stated already that I know 1.25 lads who have sub 3. In fact one fella who used to post here still has a 1.25 - he doesn't target many Half marathons or train specifically for 'em - and his marathon time is now 2.53.5x.

BUT, that is not the norm.

MrMacPhisto

HM: 81.5
M: 173
HM x 2: 163
Diff: 10 mins
10/81.5 = 12.3%