McMillan calculator times

Accurate ?

21 to 38 of 38 messages
06/05/2013 at 02:46

I've just put the same 5k time into the Fetch calculator and it shows a time over 3 minutes quicker than mcmillan for a marathon

06/05/2013 at 07:05

Rich, the one I used was the same as Literatin's link. Only gives option of a half time to predict full marathon.

06/05/2013 at 07:52

Ah OK, didnt follow the link, just went on the Fetch website and used the calculator I found on there.  I've only done the one HM so theres no point in using the time from that.  I guess I'll just work on my 5K time for a bit and get a bit closer to my previous PB and then have a crack at 10K and see if I can get that close to the predicted McMillan time and from there on to HM.  I've got a year so should have time.


06/05/2013 at 10:28

McMillan gets my marathon/ HM times pretty much bang on. People say its too optimistic over the longer distances but I've not found that to be the case if you put the milage in during training.

06/05/2013 at 10:30
literatin wrote (see)


- I'm a woman (Fetch calculator reckons that makes a difference).


Now that's interesting, partly because it does differentiate according to gender but also as it's the only one based on actual results that I've seen.  And it predicts my recent conversion to within 25 seconds.  Not bad! (Translation: I must try to get my conversion looking better than average!)

I think the main reason why formula-based predictors break down at marathon distance compared to the 5k - HM range is the caveat about being adequately trained.  It's pretty much impossible to scale up the type of training you do at shorter distances to the marathon, especially w.r.t. over-distance training, and training at race pace for anything like adequate volume without breaking down. For the race itself, I think there is an additional element of fatigue which means that the pace relationship tails off for virtually all but the best converters.  So it makes sense to have a specific predictor based on real results, and I'll be bookmarking the fetch predictor.

06/05/2013 at 10:32

...translation #2: I need to learn to run like a girl.  

06/05/2013 at 10:34

Just checked out the the Fetch calcuator and its predicting a marathon time 11 minutes slower than I got last weekend from my HM PB. Far too conservative IMHO.

06/05/2013 at 10:43

Maybe you run like a girl. Gaz?

06/05/2013 at 10:44

Apparenty I run even better than a girl!

06/05/2013 at 10:49

I think they've actually changed the Fetch calculator slightly since VLM, Phil, so your and my results will be in there somewhere. Someone on the P&D thread 'helpfully' posted the link to it the day before and I'm pretty sure it was offering me a slower prediction based on my half time than it is now.

Gaz, I run better than a girl too.  But I suspect it's secret code for 'shit at shorter, speedier stuff'. (me, that is. not you)

Edited: 06/05/2013 at 10:51
06/05/2013 at 10:55

I agree mate. I've never been sure whether to interpret the results as me having good endurance or poor speed, the old "glass half empty, glass half full" condundrum!

06/05/2013 at 13:40

I just wondered what you guys are looking at for the fetch predictions. One page, the Riegel calculator, updates the exponent used for race time calculations based on your logged pbs at all distances, so the point that one's marathon is slower than the 5 km predicts is allowed for by raising the exponent. For example, the default Riegel exponent is 1.06 whereas mine is 1.08, meaning I take a bit longer for marathons than I should.

The fetch calculator itself is here. It's not clear whether it uses the Riegel number it calculates on the other page.

06/05/2013 at 13:50

Steve, I originally linked to this one, which is based on the Riegel formula but modified based on a survey of real results, and give a less optimistic conversion (better for women than for men).

The OP went straight to the fetch calculator for all distances that you've linked to, which gives an even faster marathon prediction than the McMillan calculator.

06/05/2013 at 14:17

my 5k and half-marathon PB's were set in last few months (21.40 and 1.40.25) and match the Mcmillan calculator pretty much spot-on (not that I was aiming to do this). suggests it's fairly accurate to me. as the Mcmillan predicts 45.00 for 10k, this is now my next target.

06/05/2013 at 15:19

I don't get involved in marathons, but for a laugh put my half pb into that fetch calcualtor, and it whacked out a 2:43:xx marathon.

My pal who does do marathons has a half pb within about 10secs of mine, and just came out 2:43:xx at London.

So that one example works well

06/05/2013 at 15:40
literatin wrote (see)

Someone on the P&D thread 'helpfully' posted the link to it the day before and I'm pretty sure it was offering me a slower prediction based on my half time than it is now.

The Dastard!!!!   I really hope you never let him forget about that indiscretion as long as he lives!   Tsk!

06/05/2013 at 16:00

Well, I didn't name and shame him. 

07/05/2013 at 20:26

Thanks, L - wasn't aware of that one.

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