Realistic pace predictions for realistically shaped people

doing GNR. Was really struggling to make headway in training which was mostly 8 - 11 mile hilly trail runs, until last couple of weeks - times have just fallen away. Last weekend a very comfortable 46:15 10k on trail and 9 miles at 7:55 pace on road, today a flat out parkrun at 20:44

I know the 5k pace ought to mean well under 1:40 for a HM but I am 6'2 and have a BMI of 28. Plus prior to running I was a rower so power/lactate tolerance on short efforts has never been an issue. I feel like the standard pace prediction formula assumes a low 20s BMI and high level of aerobic fitness, because that's the typical profile in running.

Should I just be confident and go charging after a 1:37 in 3 weeks time? Or have other s found that being an atypical shape for a runner means a bias towards shorter distances?


next year I might try and fix this by losing some weight...


  • Based on your times there I can see no reason you shouldn't go for 1.37 for a half marathon. I think the race prediction formula is assuming you are doing the weekly millage required for the distance, so at least 40 per week for a half marathon and 60 for a marathon. It amazes me how big guys are able to run as fast and faster then me even though I'm 10st and thought I was quite good at distance running.

  • If you have regularly been doing 11 mile hilly trail runs, your aerobic fitness is probably much better than you think.

  • MillsyMillsy ✭✭✭
    You should be fine with decent aerobic fitness from other sports.

    I have come in to running from nearly 20 yrs of playing rugby.

    I'm not very tall and have a BMI of 26. Am now down to 18 mins for 5k, 1.25 for a half and 2.58 for a marathon. It has taken quite a bit of work over the last few years but the times have all come down slowly over time.
  • I am not the typical shape for a runner either, I have only recently stated doing parkruns so my pb is 21:01.

    I was in a simillar position to yourself last year before my first half marathon, aimed for around 1:37 and actually finished in 1:34:04. I am not sure about the GNR course but would guess its fairly flat, if you are doing hilly 11 mile trail runs then 13.1 miles on the road will be grand.

    As Seth says body shape isn't always an indicator, my GF's brother is 6''3 and well built but can easly put me to shame over any distance.

  • XX1XX1 ✭✭✭

    Assuming that you've done the appropriate training for the distance I wouldn't have thought that your shape would be an issue.

  • McMillan is bang on for prediction from my times across the board, and I've only recently edged down into the 25's BMI wise (BMI 28 last year and GNR of 1:46).  I've managed a 44:59 10K (a hot 28 C on the summer solstice) and 22:00 5K (soft time I think as was a good few months ago) this year so I'm aiming for around 1:37-1:39 as I've probably improved a tad since the PBs.  No reason at all why you shouldn't target a 1:36-1:37 HM.  I'm not sure at our level body shape matters at all over training - perhaps when you enter elite runner's times it will make a significant difference?


  • Thanks all. Less than flat out 10 mile last night at 1:40 HM pace has given me the confidence to push on. To be honest I'm still finding the limits of this new pace - gone from 8:20 to 7:40 in 6 weeks - so will probably go out at 1:40 pace and see what happens. 

Sign In or Register to comment.