Are these 'race time predictors' remotely accurate?

Today, I went for a run for only the third time in a few months and I surprisingly did 2 miles in 15 minutes 55 seconds. This came to me as a great shock considering I ran the same distance with the same effort the previous day in 18 minutes 50 seconds - a huge 3 minutes difference in the space of a day! :eek:

According to a race time predictor I found on the internet, I should be able to do 8 1/2 miles in 1 hour 12 minutes which I can't at all, with my mean time at that distance being about 1 hour 36 minutes. You can see that there is a substantial difference between my actual time and predicted time. Why is the predictor so far off?
Surely I can't have improved that much after only doing 7 short runs since my last run at that distance?

i doubt it...

it takes a long time to increase your distance...

i've gone from doing 15 miles a week to 25 miles a week... but it is seriously hard... it took me two months of blood, sweat and tears... !

btw, i know there was the marathon yesterday and 'marathon fever'* is rife...

{ *'marathon fever' = people watch the london marathon and despite doing no running before - decide to run it next year... }

but we aren't all aiming for a marathon run you know... sod the marathon... i can barely run more than 5 miles...

but it doesn't matter to me... my goal is a sub 20 minute 5k and i'm going to be doing nothing but 5k races until i get it !!!...

Yep, contrary to popular opinion, the world of running doesn't begin and end at marathons in general, and the London marathon in particular.
... But unfortunately, that's the most public face of running, and is the one which everyone expects us, as runners, to participate in. I've been a runner for over 30 years and have never run a marathon; nor do I intend to. It's not necessarily something you have to do to "prove" yourself as a runner. There's no "check-list" of achievements/distances to tick off as your experience grows.

Good luck in your sub 20 min 5K quest. You may not get your efforts cheered on by huge crowds at the roadside; you may not get your face on TV; but your achievements will be no less special when you get there.

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GONE RUNNING

Thanks... Good luck with your ankle quest... !

Thanks for that, Revenged... The battle goes on........
........ and on.

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GONE RUNNING

In answer to your original post elliot, I'd have to strongly disagree with you and say that in fact, the race time predictors are normally pretty darn good!

First of all, you have to remember it's based on statistics and therefore can only work with the numbers your give it... if you want it to accurately predict what you may be capable then you have to give it decent information...

for example... if I said to you "Today I ran 10 miles in 60minutes, Next week i'm going to run the same route, in the same whether, with the same level of effort with no extra training - what time do you think I'm going to do?" Based on the information you've been given you'd estimate the same time surely? same as the race time predictor! If your runs vary so much from day to day without you feeling any difference in your perceived energy exertion, then there's only so much the race time predictor can do.

The race time predictor also works based on the fact that your have no bias towards either speed or endurance, and that you're suitably trained to complete the distances...

I could go on for quite a while, but for all intents and purposes it's a useful tool - if you use your times from races to predict times for races of other distances not too dissimilar to that you've just completed, (i.e. not predicting a marathon time from a 1mile sprint) and are not naturally biased towards a certain distance... then it's pretty reasonable.

Oooh, and I forgot one major point... you can't really predict race times from training times, and vice versa... training paces vary massively, in races you're more likely than ever to run to your full potential - giving the predictor the most reliable info possible.

Right sorry for teh long waffly post that may not read very well or perhaps not even make tremendous amount of sense - but for me, the race time predictors have always been pretty accurate!

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www.richardsimkiss.co.uk - 'Stratford Summer Six' Race Report Added

Thanks for that Richard.

I think it probably is due to me being a bit of a 'specialist runner'. I have a comfort zone and when I run any further distances, I can't keep up the pace.

I have only just started properly, last week, and I have calculated my minutes/mile times for the 4 runs that I've done.

I did a 2 mile run at 7.9 minutes per mile but I could only do the 3.4 mile run at over 10 minutes per mile. As you can see, there is a serious difference between these two paces, but I don't seem comfortable at these long distances yet as I keep having to stop to walk.

I am going to have my first 'race' since training in about 6 weeks at about 13k so that's why I'm starting at those sort of distances. What would you recommend I do because I am doing short and 'long' runs alternating throughout the week with rest days in between and I can cope with the shorter distances in a decent pace but my pace for the 'long' distances is dire.

I find race time predictors to be reasonably accurate within a couple of minutes.

I ran a 10-mile race at the weekend, and double-checked my result on a predicator by entering my most recent 5km time. The predictor's time was a couple of minutes faster, but I'll put that down to my cold (any excuse!).

My favourite sites for race time prediction are:

http://www.runningforfitness.org/ - this has an interesting mix of different prediction algorithms and shows them side by side - I find it's very interesting to use the WAVA type prediction algorithm compared to the VO2 type algorithm (I find the WAVA more accurate for me)

http://www.mcmillanrunning.com/mcmil...calculator.htm - good for thinking about building a training programme (not that I ever do!)

It is important though to understand why you are using the predictor though...

- I don't think you should ever use a time from a "B" race (e.g. a practice race) to predict a main "A" race - I think you could set your goal too low - or alternatively you might race your "B" race too hard and end up doing worse in your A race!

- but I do think you can use a time from one "A" race to predict the time you can get at another "A" race at a different distance as long as you also put in the equivalent training for that second race.

Anyways... that's my opinion.... (gosh - what a sensible post!)

I did write a post at work but something buggered up and I lost the message - ARGH!

Anyway, I was going to say that you should just carry on as you are... a mixture of different runs is virtually always the best way to improve your overall running ability.

Come race day you'll probably find that with other competitors around you, and with race adrenaline pumping, you'll be able to sustain a quicker pace without feeling it as much (until after the race that is)

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www.richardsimkiss.co.uk - 'Stratford Summer Six' Race Report Added

I`ve just looked at the macmillan Predictor using my 5k, 5 mile,10k and half marathon times.

All suggest I should go well under 4 Hours for a full marathon.......................

What a laugh.......

obviously not putting the effort in Dave

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www.richardsimkiss.co.uk - 'Stratford Summer Six' Race Report Added

Thanks Richard..............................