IM Improvement, share your success story

Congrats on the IM!

There is no secret.  Consistent training, over time.  Whether you can trian consistently enough, for long enough to get sub-10, I can't say--and genetics do kick in at some point.  But you can go a heck of a lot faster if you train consistently across all 3 sports.  Once you reach 11, 10 will become more 'imaginable'.  So start with 11.

there's a discussion thread on the IM training forum that deals with similar question...you may find this helpful

http://www.beginnertriathlete.com/discussion/forums/thread-view.asp?tid=270106&posts=39&start=1

Here's a decent success story from recent memory for you:

http://forum.slowtwitch.com/gforum.cgi?do=post_view_flat;post=3452817;page=1;mh=-1;sb=post_latest_reply;so=ASC

It addresses the "time" issue you've mentioned as well. Lot of people put a lot of time in but not a lot of people are hammering 20 hours.  Work is a function of time and intensity so if you don't have more time then you need to incorporate more intensity to accomplish more work. 

I'd also say that there is a shift in the thought process of most guys that fast.  The don't just train and do triathlons, they are becoming it and walking the path.  There's no BS.  Drop weight and get lean, get your FTP >4.0w/kg, get your standalone marathon time down to low 3hrs, get your swim down to 1:05 without being tired.  Then, you might have a shot.  That's what it takes I'd say.

I'm trying to do something similar but I'm giving myself a couple of years before going back to IM distance to get fast and address some limiters.  I underperformed a little in my first outing but I'm looking to shave an hour off of my capability so know the thought process you are going through.

Obviously you know it's a lofty goal but good luck.  If you want it bad enough you can get it.

The only one that I can currently imagine is the swim.

I think that if I leaned out, and really worked on it:

1:00 swim

5:50 bike

3:45 run

That puts me at a 10:45 with 10 minutes of transitions.

Of course, four years ago, at 237 lbs and unable to run 1/2 mile continuously, I'd have said I cannot imagine FINISHING an IM, never mind beating my coach by an hour

Congrats on CDA!IMO, 20 hours is plenty of time to take a significant chunk of time out of your 12:43. However, 20 hours is great..if you spend it training properly. Properly depends on who you are and what your goals are, strengths, weaknesses, etc. I have my 3rd IM in a 16 month span coming up next month. Id say my volume is a bit down from previous, but my time spent is much more useful and I am seeing bigger gains now than ever before. FWIW i went from 12:4x in IM#1 to 11:1x in IM#2