Question for those who have done an Ironman

This.

Yep.  Pretty much.

You will prob. feel awesome the first couple miles.  I had to tell myself over and over to chill out and slow down. 

I did all my long runs the day after my long rides also and my legs always felt really heavy and slow during training.  You may end up thanking yourself for training this way when your deep in the run.  Its really all about proper pacing though. 

so all that to say... yes. FOR ME,  long running the day after was harder.  

p.s. who am i kidding!!  its painful, oh it hurts so so goodbut it doesnt suck.

I've done long runs day after long bikes for IM training as well as splitting them up. I like splitting them up better.

You can't really train to run on fatigued legs. I'd rather have a solid run than practice running while fatigued. The risk of injury is greater when running fatigued.

In IM training some days it feels tough and wonder how you will be able to do 140.6. Other days you do a workout and you gain confidence. I remember for my first IM, in a period of 10 days or so, I did IM distance swim, a long run that I felt great afterwards, and a long bike with strong run after. Those were the confidence builders I recall in training that turned my mind from maybe I can do this to knowing I am capable of doing this.

On IM day you will be tapered, fans, incredible atmosphere that makes a significant difference.

I firmly believe as my good friend Sue (socks) says training for IM is harder than the race itself.

Catwoman - 2012-04-28 4:27 PM  IMO- It is really difficult to say what will happen during the actual race. The run at my first IMFL was amazing. I felt great the whole time and had a really decent time. Last year at IMTX, I was better trained for the race. However, I became dehydrated and ended up walking basically the entire run course (6:42). Which is something I said I would never do. Train, put in the miles, go to the race and see what the day has for you. Regardless of what happens it will be a great day.

^^This.   Despite a bad hamstring injury shortly before the race, I felt okay about the run at my first IM.  The second one, however, went just like Catwoman's:  Dehydrated (on the bike, late) then a lot of walking (about 12 miles per my Garmin).

As you can see-it's all personal. I was under trained on the run going into my IM, but I had complete confidence. I  had a awesome bike and was glad that it was over with no issues. I went out strong on the run. Ran the first 10 miles w/o walking (my goal). Nutrition hit me hard and I probably ended up walking 2-3 miles. Once I figured out if I mixed their solution with water I could handle it, things really turned around. I still walked/ran but did much more running.

It was my first IM. It was actually my first marathon. My goal was to finish in 13 hours (did it in 12:30). Next time, I'll have different goals. I always looked at tired training days as being more realistic for race days.

This is how I feel!!!  Those good strong training days bring on the confidence...however even the bad days, when I get through them....make me feel like I can overcome difficult times in the race.   8 weeks from today!!!!  How can one be so excited and so full of dread all at the same time!!

This was almost exactly my experience too.  I spent the first 13 miles or so holding back, and trying to slow down, because I was running a few seconds per mile faster than I had done my long training runs, only walking at aid stations.  Then it hit me around mile 16 or 17 really hard.  It was pretty ugly for a few miles of steady walking to recover, then I was able to tough it out to run in the last couple miles strong(ish).  My split was something like 5:15.

I totally agree that the training was harder than the race and that everyone is going to be different.  I had done 10 stand alone marathons before my first IM.  I'm not a fast runner (by most people's standards), but I knew I could cover the distance, so I knew once I got off the bike I would be fine.  I planned (and trained) to do a 4:1 run/walk ratio.  When I got off the bike my legs felt fresh and when my garmin beeped at me to walk I wanted to keep running, but made myself stick to the plan.  

I was able to do the 4:1 the whole time.  I did skip one of the run portions toward the end to soak in everything as I got close to the finish, but I was capable of keeping the 4:1.  My marathon time in my IM was only 20 minutes slower than my stand alone marathon PR at the time.  I have a new marathon PR now, so we'll see how my second IM goes.  I'm hoping for similar results, but you never know what the day will bring.