Gotcha! You guys saved my IM!
I just searched the web and got similar opinions as well :) http://home.trainingpeaks.com/...ronman-marathon.aspx Get as strong as you can on the bike
The inaugural Ironman Wisconsin, held in 2002, featured a novelty. A couple of elite Kenyan runners did the race. Iím talking about sub-2:15 marathoners. The story was that some coach had recruited these guys as a sort of experiment. Anyway, not only did the poor guinea pigs get crushed on the swim and the bike, but they also ran terribly. This unique example demonstrates that the first key to running strong in an Ironman is not pure running ability but strength on the bike
It makes sense, right? Your bike fitness has to be at such a level that you can ride hard for 112 miles and still have something left for the marathon. All of the running fitness in the world wonít help you otherwise. How do you get that strong on the bike? The short answer is by putting in a ton of volume. But most of us donít have enough time to put in the optimal amount of bike miles. So then, what is the least you can do to build enough bike fitness so that 112 miles is no big deal?
That's about right. Bottom line, for me, is that if I fail to reach my goals in an IM it'll be for one of 3 reasons: not enough bike fitness, riding too hard for my bike fitness, or not fueling well enough. If I run a 3:45 marathon, I won't be thinking that I should have done more running.
The % breakdown of your training hours will vary a bit based on your background and skill in the 3 sports. You may also find that you just enjoy running too much to cut back, which is perfectly understandable, even if it's not ideal.