I did San Diego in June before IMC in August. Also did Disney in January before IMC. This January I am doing Disney, then perhaps a May marathon and then IMC (still in august). I am not a fast runner so It wasn't like I was out busting a gut though. June is a long way off from November, so I don't see why not.

If you want the confidence that you can run that far, or the marathon experience, and you aren't having any injury issues, and you have time now to safely increase to the distance, I'd say go for it. Late spring and the recovery shouldn't really affect a training plan for a November Ironman.

However, if it is your first marathon and first Ironman just be aware that marathons do have a fairly significant recovery time for them (depending on how you heal, that is). Just be ready to have to let your body heal -- it can be hard if you have trouble taking rest time :)

Don't feel it is required -- many very successfull Ironman racers don't do standalone marathons. I think it's just a personal choice.

I'm doing my first IM in 2009, and my coach advised not to do a marathon as part of training for the reasons Kylie and triNick said. The recovery time is long and, as the argument goes, you are better off just building the triathlon training without interruption. A HIM a couple of months prior to the full could be a good idea, and you can use it to work out nutrition and pacing issues. And the recovery time isn't nearly as long as for the marathon.

If running is your limiter, then there are other great ways to work on running within a normal triathlon training plan, the biggest being run frequency (running 4-5 times a week, including one long). I've recently read blog entries by Chuckie V and Brett Sutton talking about how THE BIGGEST cause of slow IM marathons is the bike, not the athletes running potential. Without proper IM bike endurance even the fastest marathon runners walk most of the marathon, simply because they can't do a 10+ hour event (or they pushed too hard on the bike). But I guess my point here is that you shouldn't put all of your effort into the run, because the bike training is critical. If you have time to do many many hours a week of cycling and still train for the marathon, maybe it will work out for you. Everybody is different.

The benefit from running a marathon does not outweigh the risk of injury or the amount of time to recover. If you were going to do it, I would suggest training for one right now and run it in January. This way you'll have time to recover before you start training for the November IM.

Hey, if you need the t-shirt go for it.

I take it you aren't trying to win the thing? Then you won't be pushing the limit and it is just a stepping stone. My first IM was in late August. I ran a marathon May7th and was fine for the IM. I wanted to prove to myself that I could at least run that far without the swim/bike parts. It worked for me.

Haven't bothered since though.

PoC