I’m doing IMCDA, which will be my first! I’ve complete 50+ sprint/olympic, Keauhou Half x 2 (BT4:45) and run 7 Marathons(BT3:10). I’m trying to figure out my “ballpark” finish time for IMCDA.
I’ve heard you can take your half time and double it adding :45-1:00. Is this very accurate? Does anyone have any experience with half to full? I realize several factors can play into this, but I’m just trying figure out a “ballpark” finish time.
Thanks for the feedback!
I’ve heard the “double plus an hour” before. I use a factor of 2.15 (which is pretty close to your “double plus 0:45”) for a theoretical lower limit. Your endurance and race plan have to be excellent to achieve this, though, but I know athletes who have so it is possible. I have also seen athletes go 4:12 for a 1/2IM and then do a full in the 10:30 range. For my first Ironman, my 1/2 to full factor was about 2.4 but with experience I have brought that down to about 2.2.
All things being equal - which they usually aren’t - double plus 45m to an hour may give a good idea of the best you can expect - however to prep yourself for all eventuallities double plus 2 hours gives you a worse case situation - an iron man is all about the last 20 to 30km of the run - that makes or breaks your day - if you go to hard on the bike or early in the run you can easily loose an hour or more during this section of the race
.
I’ve done close to a dozen 1/2 IMs and none under 6 1/2 hours. My 2 IM finishes are 12:36 and 12:49. Conditions play a big role here as they’ve been brutal at the 1/2s and favorable at the IMs.
Even so, I was pretty accurate on estimating my finish time for my first IM without using my 1/2 times as a base. The swim was pretty easy to guesstimate. I knew my pace for a moderately hard century ride and used that for the bike time. The run was the big unknown. For that I looked at my worst marathon time where I barely finished alive and figured that was probably close to what my IM marathon would be. Factoring in transitions and some time cushions I came up with a time between 12 - 14 hours with 13 hours being likely. MY actual finish time was 12:36.
You might want to look at more that just your 1/2 times. Examine each leg of the race and assess the conditions in which you’ve raced previously and the conditions that you expect to face.
Good luck.
Larry