UKH

Never timed myself in the past but I recently ran a timed 5k at 16:58, didn't mean much to me because im not aware of 5k times, however i put it in some race calculators which said it meant i could do a marathon at 2:42-2:46 which sounds awesome to me.  Is this realistic or are they often way off at longer distances, what are other peoples experiences when using them? 

In reply to climbercool:

what is the best website people use for running forums?

In reply to climbercool:

I reckon they're pretty accurate up to HM. Not done a road marathon (currently training for London this October) and the pace I'd have to run to hit my equivalent time seems v optimistic at this point!

In reply to climbercool:

Those calculators seem pretty accurate for me but all come with the "with equivalent training" caveat.

Personally that makes sense - my 5k and 10k times align well. My half marathon is slightly slow and my marathon is really slow because of that caveat - I don't have the endurance as I haven't run enough miles.

In terms of forums, LetsRun seems to be the go-to but it's a complete cesspit of right-wing extremists, conspiracy theorists, racists and misogynists with some great running experience mixed in. Fortunately it's now possible to filter by running.

Edit: well done on the 5k by the way - that's bloody rapid and you must have some talent.

In reply to Tom Briggs:I haven't found much good discussion about them online.  But what i have read are all similar comments to yours, that they work at the lower levels but when it comes to marathons people are much slower than predicted.  I think i will start marathon training soon so I will find out one way or the other.

In reply to climbercool:

The physiological requirements to run a fast 5k versus a fast marathon are quite different so I'd be pretty sceptical of this. If you are doing lots of aerobic capacity training and really just running 5k's off your base then maybe. But if you've been training specifically for 5k's then I doubt it's going to carry over into a much longer distance that well.

In reply to compost:

thanks , yes really psyched with that time, but mainly because of what it says i can do in a marathon.

ill check out the LetsRun website

In reply to Ben Harris:

i generally run for about an hour so not been training 5k, i guess that's a good sign.  

im interested to know if there is anybody who can run a sub 2:45 marathon but cant run 5k in under 17 mins

In reply to climbercool:

I suspect there are quite a few, the marathon time would certainly seem more realistic than the 5k for me although I've never actually done a marathon on tarmac. 😀 

In reply to climbercool:

The person that I know of around this time runs 5K at 16:45 and has run a 2:41 mara. I also know someone who has run a sub 3 mara whose 5k pb is 19:45. That would put them at the very-fit-but-not-naturally-fast end of the spectrum I would've thought.

In reply to climbercool:

I know a good few sub 3 marathoners who can’t  get near 18 for 5k, which is almost the same.

In reply to gazhbo:

this is giving me confidence

In reply to climbercool:

Sub 17 5k is very rapid, have you been doing speed work/intervals in your hour long runs to achieve this? If not even more impressive.

I would think 2.45 for marathon would be quite acheivable with enough endurance training and avoidance of injuries.

In reply to climbercool:

Sounds about right. My 5km PB is 16:2x, I think run a few months after a 2:42 marathon (bit of cramp robbed me of a minute maybe). 10 days before the mara I ran a 33:58 10km.

I was in shape where in the race we were knocking out ~6:07 min/miles, to about 16, then we started cracking out 6s as had paced well. Even with the cramp attack I was hobbling 6:30s.

That was after a good few months fairly specific block - XC season, marathon style long runs. I always consider myself better and consistent over longer distances.

In reply to climbercool:

I had a look at the people who have run ~2:45 for a marathon this year on Powerof10 (link below). Most seem to have 5k times between 16:30 and 17:00 and/or parkrun times between 17:00 and 18:00

Some have no times over such short distances, and a few have 5k PBs significantly above 17:00

Of those on Po10 with 5k PBs just under 17:00 who had run marathons, PBs varied between 2:30 and 3:00, with a bias towards the shorter end of that.

Make of that what you will - this is clearly not a comprehensive analysis.

https://www.thepowerof10.info/rankings/rankinglist.aspx?event=Mar&agegr...

In reply to tlouth7:

oh, that's just what i wanted to see, very interesting.  Just hope i don't waste too much time looking at random peoples running times.

In reply to climbercool: They are good for 5K and 10k, maybe 10 miles , but they start breaking down when you get to 1/2 mar and beyond as you start to need to assume a certain volume of training and natural ability will only get you so far ( about 2 hours in my experience)-.

You get good equivalency if you add 1 second per hundred metres every time you double distance.  Works all the way from 400 up .

16.45 is ok for running on talent alone, and a bit of basic fitness. 2.45 marathon gives you a long time with plenty potential for things to go very wrong.

In reply to climbercool:

Not much to add here except well done for an impressive 5K time! Mine is currently about 3 minutes slower so I'm jealous.

Even when I was properly marathon trained and felt like I'd had a good race (rare, and I've run a few of marathons), I didn't hit the time the race predictors said. The marathon is unforgiving if you have not got your hydration and nutrition right before and during the race, or the weather isn't perfect, or you've slept badly, or etc. so it might take a few goes to hit the time you are capable of. Or not, if you get lucky (or get everything right) on your first one.

In reply to climbercool: I just had a look at this time in some equivalency calculators and got the same result.... no surprise.  My comments...  it's equivalent to a 5 minute mile as a mile pace, and if you have moderate fitness and a lot of natural speed that might actually happen.  Ditto 3k, no surprise.

It's more problematic as you go up... ie 35 minute 10k is possible , but might start to feel a long way.  How much running are you doing? Because when you translate up to a 1.15 half marathon, well then you have a lot of time to get tired and for things to go wrong, and minutes go very fast. 

Move up to the marathon and the problems go thro' the roof for the ambitious runner... you've dropped from 5:28 tp 6:13 a mile , but you'll be out there getting on for 3 hours, a long time....  I tihnk the calculators work, but assuming they work for people with no training base isn't so 

In reply to wbo2:

My understanding is that they are based on the athlete training for the specific distances. They won’t be accurate if you don’t train for speed as the distances get shorter, or endurance as they get longer. They are obviously also an average and don’t account the quirks of individual athletes.