It was just that you said you've raced a half ironman, and the rest were half marathons. That's one bonk whilst racing! (Admittedly I had not thought about any cycling races you may have done).
Sorry, no offence meant. The point I was thinking of was pushing your body so far that recovery hinders your training schedule. In training, when you bonk you can back off, making sure you can recover, but when you are in a race, you try to keep your effort level up. This means that you are putting yourself under a lot more stress. Almost all the damage done to the body in a marathon is on the last 6 miles. The body is telling you to slow down, but you are over-riding it and damaging it even more. Thus the hole in your training schedule that Gordo dreads so much. Mind you, with 24 years of experience, this is probably not telling you anything new.
As you're a cyclists, maybe you can help me with a question I've got. I live on the North Downs, which means lots of hills. I can't do steady, low heart-rate rides as a result. I'm not exactly slight, so my power-to-weight ratio is ludicrously low. I struggle, and my heart rate soars. Is this a problem, and should I get a turbo trainer to replace these rides?
BB