So I may be crazy...

Your rotations will start July 1 - unless you are just a first year now....

Yeah I'm a first year now. 2nd starts Aug 2009 then rotations summer 2010.

You will probably hear from some of the other docs here, but I'll offer you my opinion. To give you an idea where I am coming from, I started triathlon in my second year of residency, and did primarily Oly's for the next several years.  We also had our first kid in the middle of med school, and the second in residency (right when I started to train and race), so the idea of trying to balance school and life is familiar.

It might be possible to get in the training volume while you are a first year student.  If you do so, I recommend having a back up plan to bail out.  The amount of material you need to master is insane, and it can be hard to be motivated since (except for gross anatomy), a lot of it seems less immediately relevant.  It is hard to fail out of med school (you had to be pretty smart to get in), but not impossible.  If you are running into your limits and have to make a choice, don't bail on school, but shift your training to shorter races.

It may actually be easier to plan to race an IM at the end of your 4th year.  That's mostly electives, and by the middle of the year, you should have a fairly good idea of what specialty you are going into, and where you want to go.  Since you can take a light load (or maybe even a block or two off at the end - I did to save child care expenses in the last rotation), and not have to start residency till July, you can get a solid couple of months in early summer of training.

Residency can be tough on training, depending on the specialty.  Some areas are more lifestyle friendly than others. You will have paid vacation time, the amount depending on the program.  But if you get a trainer for the bike, and use a treadmill, the hours you work in residency won't matter. You can train at 9 or 10 at night without any problems. Like I said, this is when I started my training, and I raced all the way during my residency, while raising 2 kids (mrs gearboy is also a doc, so we had equal amounts of work and split the child work evenly, since it was not reasonable for me to play the "but I'm a doctor!" card).

Another good natural break in medical training can be between residency and the real world. Depending on your circumstances and specialty, you might be able to wrangle a month off between the two.  I did so, and used 2 weeks to go backpacking in the Sierras (where no one could page me or have any demands on me whatsoever). It can be another good point for intensive training to finalize for a big race.

Crazy! Insane! Great idea!

Hope everything is going well for you.  Good Luck!

Mercy might be taking over Saint Johns (Clinton Area Amb), you're missing out back here...

More power to you!!  I could not imagine doing IM training with 70 hours weeks, but that is probably because of an acute triple case of irugamus iratamus.    Congrats on working so hard towards an awesome profession.  It takes a lot of sacrifice without the level of reward it used to have. (not personally a MD, but I've been a family member of one for 33 years, so close enough)

I think you are actually pretty smart since the first thing you are considering about doing an IM is your availible training time. I think LOTS of people fall in love with the idea of IM and don't think about the actual weekly time it will involve.

I'd HIGHLY recommend hiring a coach if you can spare the cash at all... will help you put together a reasonable schedule so that you don't have to think, adjust, etc as well (which can be a big time consumer).  I've been reading the stuff from endurance nation (http://www.endurancenation.us) recently... and they put a huge emphasis on lower volume higher intensity IM training.  10 hour weeks kind of thing, which some very impressive anecdotal results to back it up.  Please note this is not an endorsement of their stuff, as I am a bit leary of how unconventional some of their techniques are (I plan to start a thread soon after I digest a bit more)... just a referral for you to evaluate yourself (that said, I am strongly considering using their plans).

I think you can do it, if it's important to you.  But between work/school and training, there won't be time for much else and you'll have to make sacrifices.