I just wanted to come back to Mr. P's post mostly because of some of the comments. I can say that I did do two marathons and one ultra, before my first IM. I have now done four IMs and have had terrible "runs" on two, meaning I felt like crap, and two runs that were comfortable even if not speedy.
Like others, I agree that a stand alone marathon hurts more than a marathon at the end of an IM. I had experienced friends tell me that in advance and so I just trusted in their collective experience and didn't worry about it.
So here is my departure, comments to the effect of not doing a marathon during the course of training for an IM…not even in the same year as an IM. I'm puzzled as to why that would be the case because I have heard it so many times. Here are my thoughts.
Recovery - good reason but how long exactly does it take to recover and how thoroughly are you trying to recover?
Performance – sure, you are unlikely to be at peak performance if you show up "over-trained" but what kind of peak performance are you looking for? I always have time goals but they end up taking a back seat to my goals of finishing and having a good time. I can't divine any importance regarding the time difference between my 14:20ish PR and my 15:50ish fiasco. What if I got what would be a dream time for me of something in the low 12s or even a sub 12? Well, if I did pull off a sub 12 I would probably obsessively follow every training rule to see if I could "shave" another TWO HOURS off my time so I could pretty much be guaranteed a slot at Kona.
Avoidance of injury – excellent reason…however you don't need to be racing to get injured, heck, you don't even need to be training.
Time and cost – as far as I'm concerned the best reasons, let's face it we did not choose the cheapest nor most time efficient sport.
Personally, I am doing a shameful amount of marathons and beyond this year, enough even to embarrass me, and the only thing I think I will really GET out of it is maybe the ability to more happily plod along if my IM does go awry. On the other hand I did just cut almost an hour off my marathon PR and about 45 minutes off my 38 mile PR so the running is doing something.
So, why not do a marathon in the lead up to an IM…why not a few…what are your reasons?