Talkback: How to predict your Ironman time

8 messages
29/12/2014 at 21:26
It looks to me as though the brackets are in the wrong place. I think it should read 186.3 + ((1.595 × PB for Olympic-distance triathlon) + (1.318 × PB for marathon)). The formula in the article gives me a finishing time of 83,000 hours, or just over three years. I don't think I can carry enough gels for that. But calculating the PB ratios first, summing them and then adding 186.3 gives me a predicted finishing time of just under 11 hours, which seems a bit more reasonable
29/12/2014 at 21:28
It looks to me as though the brackets are in the wrong place. I think it should read 186.3 + ((1.595 × PB for Olympic-distance triathlon) + (1.318 × PB for marathon)). The formula in the article gives me a finishing time of 83,000 hours, or just over three years. I don't think I can carry enough gels for that. But calculating the PB ratios first, summing them and then adding 186.3 gives me a predicted finishing time of just under 11 hours, which seems a bit more reasonable
30/12/2014 at 07:15
20% difference between actual and estimated, and in a LD race 20% is a very long time, I would have been happy with a 5% variation but 20% is too much.

Only the true self,which transcends the personal,lays claim to immortality.
30/12/2014 at 14:43
Hmmm, predicted time: 11hrs 46mins. Actual times 11:06, 10:41, 10:12.
Ironman isn't about how fast you can do shorter distances or how fast you can do the swim bike or run, it's about how fast you can do them all together.
01/01/2015 at 01:09
Within ~2% for me. Interesting (and the brackets are fine of course - multiplication always preceding addition unless brackets dictate otherwise).
01/01/2015 at 22:46

Here's an easy way to work our your predicted Ironman time:

Take your half Ironman time, double it and add an hour if your time is under 5 hours. If it's over 5 hours, add 90 minutes.

Simples!

Now, the technicall bit: If you don't own a powermeter, or ignore your powermeter, or don't know how to use your powermeter, or ignore your heart rate monitor, or believe you can race by feel and all this technobabble is rubbish, add on another 30 minutes.

If you're an alpha male and like to zoom past people on the bike, add another 20 minutes.

If you are convinced that sports nutrition is not necessary and malt loaf will do just fine, add on another 15 minutes.

If you didn't practice changing punctures, add on another 15 minutes.

If you didn't get your bike serviced and at least change your chain, add on another 10 minutes.

If you decided to ride in new shorts, or decided to save 30 seconds in transition by not putting some chamois cream on,  don't add any time on, but it sure will feel like you've added 30 minutes.

If you decided to run in new shoes you bought two days earlier at the expo and tried out for a 20 minute run and they felt fine, add on another 15 minutes.

If you bought calf guards at the expo and are trying to put them on in T1, good luck to you making the cut off

I'm only being slightly tongue in cheek here


oxygenaddict.com Triathlon Coaching

04/01/2015 at 15:26
Predicted time was 2.5% more than actual time for me but I have only done one iron distance event so hope to improve on that. Agree that formula is a little confusing but I was never great at maths.
04/01/2015 at 16:39

I always enjoy this question and really liked Rob;'s comments. He covered everything except of course to factor in the weather. Which you can only do on race day in the UK as its the only time you might have a chance of predicting that.... Cheers Jay

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