I would definitely NOT start an IM training program feeling "burnt out". I think 20-24 weeks should be plenty of time to get in a good training program. Especially after 8 months of training - you should have a pretty solid base going into your training. And I don't think you'll lose much fitness in only a month, as long as you continue to do some cross training. Use this time to do some strength training at the gym, etc. which will help a ton in your IM training, but will keep you off the bike, road and pool so you can mentally recoup.

Bottom line - IM training isn't something to BEGIN mentally drained. I think once you determine where you are at, mentally, in a month, then you can start thinking about your goals for the race and the related training program you'd need to help you accomplish those goals.

you'll need plenty of mental toughness left in the last month of your training. I just completed IM Wisconsin and in the last month of my training i needed every bit of mental toughness to push me through the training and a plethera of bad luck!! I had so many bike problems in that last month it was about to make me go nuts! During a long brick, my chain broke and got caught in my rear derailleur and ripped it right off the frame. I called my wife, who was nice enough to come pick me up, and I put on my running shoes and still did my run. During my longest ride, i got caught in a TORRENTIAL downpour during my last 30 miles and just kept hammering away. During my longest brick, I scredded my back tire within the first hour of the ride. I drove home, put my wife's back tire on my bike and sat on my trainer for 3 hours (that's painful) and still went out for my run.

Bottom line is, first and foremost, get yourself mental prepared b/c you'll need it. Things, other than your planned training, will come up. If you're not there mentally, this little things will eat away at you and keep you from your goals.

I was planning on taking at least 2 weeks (probably a month) where I do no organized training, only ride or run when I feel like it and do some weights etc. I will see how I am feeling mentally then and make a decision. I appreciate the warnings on the commitment needed though, its easy to get excited in the post race environment and I will need to think about this seriously.

Thanks !