Marathon or Half IM, what comes first?

Whatever you want

Like the previous poster said, it will be harder to do marathon training while IM training, so I think it's probably smarter to do the marathon in the fall of 2014. That said, if you want to do an IM in 2015, it's probably best to have done a (couple) HIMs beforehand. It may be smart to put the marathon off for a while until you finish your IM.

(congrats on getting off the couch and making the commitments! sounds like you have a great plan )

In my opinion, a marathon is substantially harder than a HIM.
The HIM takes longer, from an overall time perspective, but the marathon takes a much more significant toll on your body.

If I were in your position, I'd want to complete a marathon and a HIM before tackling an Ironman. But, since most Ironman training plans have you schedule a HIM along the way (6-8 weeks prior), I would lean toward rounding out 2014 with a marathon.

Personally I'd do a HIM first at the end of the season as you'll be tri training all summer.  I know people that have done a IM without running a stand alone Marathon beforehand.

You don't need a marathon. A HIM will help you practice nutrition.

If there is one piece of advice I would give you. Don't rush to the longer distances.

Do the HIM. its a long race and it won't stress your body as much as a full marathon. it only took me 2 weeks to recover from my first HIM this year and im still recovering from my first marathon which was in october. 

The marathon will likely be substatially harder on your body both in training and racing than the HIM. Don't 'mistake the longer race time of the HIM to imply a harder race - the toll of the pounding from the marathon will humble you. 

I would do the HIM first. Having run 10 marathons in the past and recently done 2 HIMs, I'd save the race with the most damage/pounding in training and racing for later on when you're at your strongest with the most experience. 

You don't need to do a stand alone marathon to prepare for an IM.  Two completely different things.  You can certainly do the marathon if you really want to, but if you do, I would space it out as far away from your IM as possible.  Don't underestimate the amount of recovery needed before you can resume normal training.  2-3 weeks is typical, sometimes longer.  Add in the fact that you likely won't be swimming or biking much while in the last 6 weeks of marathon training and you can put yourself into a pretty big "tri training" hole by doing a marathon too close to an important tri event.

Not really opposed to doing two HIMs, but I'm not sure where you live and how training might be like over the winter.  I live in a very mild climate where I can SBR year round with no issue, so an early season HIM wouldn't be a problem for me...but many people who actually experience winter may find it more challenging.  Just something to think about.  Some people instead do a semi run focus and shoot for an early season half marathon to start off.  A half marathon is great because it requires less sacrifice on the swim and bike training and has far less recovery impact after the race as compared to a marathon.

Not really trying to sway you either way...just something to consider as you seem new to the sport and don't have a full year under your belt.  Best of luck.

that race schedule (and presumed training that goes with it), should be finished off with an HIM.  A marathon benefits from much more running than you'll have time to put in. and, as stated above, and is unanimous- an HIM is easier than a full mary.  

not that 'easier' should make it your goal, but with only 5 weeks after your last Oly, there's no time to do a running build unless you put your marathon off 3 or 4 more months.

Other than agreeing that a stand alone marathon is of questionable value for someone with the goal of an IM, I'm going to ask a question.  Why the rush to an IM only two years after coming off the couch?  As a very general recommendation, and knowing nothing about you, I'd suggest getting at least one more year of endurance sports behind you before taking on the training load needed to have a good experience at the IM distance.

Half Ironman. Learn or re-learn how to bike at the right pace and dial in your nutrition. Those two things are going to be more important to you on IM Day, then having run a marathon. If you are really intent on running a marathon, then do it AFTER the HIM, once your fitness is pretty solid.

PS - don't listen to the crazy runners on this website. You don't have to run a marathon before an IM. ;-)

Originally posted by simobk Again, thank you all for your input. About some of the questions that were asked : - I should have made it clear that off season is REALLY off season where I live (Montreal, QC). My 5k race yesterday was done on -10°C (14°F) and on icy terrain. Basically, except for 5 or 10k, there's no real race between November and March. - About the "rush" to do an IM in less than two years : I got out off the couch by promising myself to finish an ironman for my 35th birthday. That's my motivation, that's what I want to reach. I already had to delay it to June/July because there's no way I can do it in March...

Oh! You live in the cold! You can still do race simulations on the winter - whether it's on the treadmill or bike trainer. Just b/c it's not something you sign up for, doesn't mean you can't go hard! Be creative and test yourself every few weeks with 'race simulations' and fun workouts that push you.