Pace difference between HM and M ?

[Bazza1234]

For any here who have experience of running /runwalking/walking BOTH a HM and a full M - I am wondering if you could contribute your thoughts about the difference in average pace between the two types of race that you have achieved. There are articles on the Internet including quite large studies of past results regarding this but I fear these may come from more experienced marathoners than those who we have here (please forgive me!) Essentially looking for your average pace for a completed HM and M . I have never attempted a full M but have done 3 HM's - I feel that I would need to aim at an average marathon race pace of 30secs to 1 minute per Klm slower than the HM

[Lordi Marathon]

For me, my HM time 02:09:10 pace 6:10 m/km was without walking at any point, not even through the water stations. I can say I was actually " running" (well not very fast but running all the same). On my marathon I deliberately set off at slowest jog pace because as it was my first marathon I was only interested in finishing. My marathon 04:51:23 pace 6:55 m/km was with walks through all 9-10 drinks and fuelling stations, sometimes I walked for up to 30 seconds eating a banana or taking a gel + drink. I did the first 21k 10 mins slower than my HM time and then lost a further 23 mins over the last 21k. So for me the rule of thumb for a marathon estimated time of taking your HM time, doubling it and then adding 30-40 mins was about right.

Edit - So yes, about 45s per km slower for the marathon.

[Bazza1234 Marathon in reply to Lordi]

Thanks - this agrees with my theoretical thoughts on this matter - but also with some other articles I have read that say that say 2xHM time +20to40 mins ( ie 30secs to 1 minute slower than HM pace. )

[Bazza1234 Marathon in reply to Bazza1234]

Of course, it has to be recent HM pace- my 2:20 HM 18 months ago doesn't count!!

[roseabi Ultramarathon]

My best marathon and HM times were both on pretty flat courses - Brighton and Oxford respectively, and within 6 months of each other. Brighton average pace was 6:05 min/km, and the Oxford Half 5:36, so my paces then were about 30s apart. I walked a fair bit during the second half of the marathon and achieved textbook positive splits 😊 Same as Lordi I ran all of the HM.

I also did the Brighton Marathon (6:17 min/km average pace) this year and the MK Winter Half (5:41) a couple of months before it - roughly 36s difference in pace. Did both a bit more slowly and with walking - walked through all the water stations, that's been my main tactic this year!

[Bazza1234 Marathon in reply to roseabi]

Two replies so far with almost identical results ( in terms of pace difference between HM and M )