IM to HIM advice please

I think the structure of the training plan depends on what you do leading up to it.  if you keep up steady training, then there's no reason to do an 18 week plan.  You can build for the HIM with 8-12 weeks of HIM-specific work.  But if you let the consistency of your duration/mileage fall a lot during the off season, then you'll want a longer plan that helps you "rebuild" your base.

My own plan is to generally keep up consistent training in the off-season.  Probably a bit less biking (but more intensity) which will drop my overall time volume somewhat.  But adding some run frequency (and maintaining a solid long run in the neighborhood of 2:00) to work on this "limiter" for me.  While I could also improve my swimming quite a bit, this year I think I'll more likely just look to maintain which will allow me to drop one of my 3 swim sessions if I want to as well.  Though if I'm unfortunate enough to develop any running injuries, my fallback plan would be to swim a lot and get some coaching.

Hope that helps some.

From the BT desert,
John