LB70, a few days ago I described my recent HR based training plan. The person who came up with this particular variation on the HR-based theme called himself HADD and posted lots of stuff on the letsrun forum. Anyway, there was a thread about this plan http://www.runnersworld.co.uk/forum/training/hadd-training-method/260438.html and the first post has links to documents about it. Might want to skim this particular document http://www.angio.net/personal/run/hadd.pdf and see whether it resonates with you. This helped me immensely and now I think I need to change things up. You may be at a point where you have good shorter distance speed but need to develop your aerobic engine more. That's really what this plan is all about.
BTW, FIRST does not appeal to me! I love running too much and cycling too little (but must reverse that trend at some point for longevity sake)
Undecided on what my next race will be. I have a heavy workload through October so the smart move would be to bin a fall marathon. But each day am thinking I might do the Baystate race again in October. It's pretty flat and temps have been perfect the past 2 years. Tempting. I could still try to do some faster stuff early summer and then try a different training plan (Hanson's or maybe even just good old P&D) to get some more speed build in. Nice to see all the other targets on the wall though. Will be fun to see how everyone fares.
Did 6.5 miles tonight and everything felt really good.