I should start with targets, because they matter much more than the history.
First, my current goal: run Boston Marathon in 3h25'. Then I want to run some trail 50 miles or longer ultras with a good pace. Recently, on October 12-th 2013, I ran the Baltimore Marathon in 3h34'44". It's approximately 5 minutes better than my a year-old results of the same marathon. But I was trying to get it in 3h25', and until mile 16 it looked very achievable. On mile 16 my hamstrings started cramping. Especially on downhills, - where I was usually passing other runners by relaxed running "without brakes". And I planned to accelerate from mile 16 to 20, and to run fast last miles of the marathon which are mostly downhill.
I thought this cramps may be helped by gatorade and last capsules. I've slowed down, drank 3 cups of gatorade with 2 salt capsules, and continued through the course. Even was able to have good miles, like mile 24 in 7'51". I'd like to know, what was my mistake causing these cramps. Is this just insufficient hydration/electrolytes, or I needed more training of some kind? I was drinking on each aid station which were once each 2 miles, - once water next one gatorade. May be missed one or two of these stations. My run is recorded at http://connect.garmin.com/activity/389492038.
Some specific details: I am Jewish, not driving on Saturdays, and this marathon was on Saturday. So I had a good warm-up 7.5 miles from my home to start line of the marathon. I ran it easily and drinking a lot of water and juices.
My training context: in August I've started 5-mouth training program from the book "The Cool Impossible". It changed me very much. Before this program I was mostly running long runs, with pulse rate about 110. The first HR zone per the book for me was 127-136, and it was as hard for me as first SP zone. I miss my very easy runs! I completed 6 weeks of Phase 1 and then decided I should do some marathon specific training, - tempo runs and yasso repeats. And had a tapering for last week before the race. The average time for half of the mile in yasso repeats was 3'26.07", with maximum time 3'34.8".
Should I return to the week 7 of the training program of the book? It will be completed at the end of January, and I will have 2.5 months before the race. What kind of training I should do in these 2.5 months?