Home Chat General Chat

Ironman marathon - how fast?

Hi - I'm doing my first ironman (Austria) this year and am trying to set myself a goal to work towards. My overall aim is just to get round, but I would like to have some sort of time to aim for as well, just to motivate me when I'm training.

My marathon PB is 3.48 - based on this, what do you think would be a realistic time to aim for? I know there won't be an accurate answer to this question, but I'd be interested in what other people have found the differences between their marathon times in a straight run and in IM to be. Any guidance from experienced IMers will be welcomed gratefully!

Thank you


  • ardkeenardkeen Posts: 152
    The bike is the most important determinant of your time. A friend of mine did IM UK which is ranked tougher than Austria in 12hr 36, and he would have a similar run time to you normally. All I would say top you is your time depends on what training you put in and nothing else, and train smart.

  • bathtubbathtub Posts: 280
    Its a difficult question to answer really as there are many factors affecting your run split, training you have been doing, heat on the day, how hard you rode the bike leg, run terrain, your nutrition and fluid intake.

    I have a marathon pb of 3.17, I ran the Longest Day run split off a good run training build up in 3.53. In 2006 after a couple of months off with a running injury plus 25 degrees heat I ran Roth run split in 4.41.

    Last year a mate of mine ran the London marathon in 3.24 yet his run split for Ironman Switzerland was 5.05.

    Sorry its not much help to your question but I think it shows the difficulty in predicting an IM run split from a straight marathon split.
  • feesfees Posts: 28
    My marathon PB last year was 3h44 and I ended up doing 4h23 at IMSA. Aiming for a 4hr marathon at this years IMSA.
  • pacmanpacman Posts: 109
    I reckon train at the pace that suits your run but on the day be very felxible to how you are feeling at that time. My marathon PB is 3.29 and i did the run leg of IMUK in 4.16. The thing is though I felt pretty good going into the run and had taken it easy on the bike for a total time of 12.09. As previously said a lot depends on the weather and training, but I think a lot depends on your ability to take in carbs along the end of the bike and the run.
Sign In or Register to comment.