For the next three months, I will be focusing my long training runs on two different types. They are called the long steady distance run and the fast finish long run. I've bought into this a bit from Greg McMillan's site. I'm not going to run these exactly as he describes, but I feel that alternating these two types of runs will be beneficial to my marathon training.
With so much of my training focused on ultras last year, most of my miles logged were quite slow and low heart rate. Then, with a stress fracture last fall, running was very slow, just so that the healing of my tibia could complete.
I've got a great aerobic base right now, but don't have the top end speed or the fast efficient stride need to be a better racer at the marathon distance or less.
Long steady distance run:
I ran this type last Saturday. 18.4 miles on rolling hills. I went into it with very low glycogen levels, as I had restricted calories to under 1,500 per day for the prior 3 days.
Ended up averaging 8:38/mile and was totally drained by the end. Total glycogen depletion!
Fast finish long run:
Today was FFLR day. The plan was to go out at 8:00/mile for 12 miles, and then step up to 6:52/mile for the final 5.
Execution of this plan was almost perfect:
12 miles: 7:58/mi.
5 miles: 6:40/mi.
I took a gel at mile 11.5, and that was plenty of fuel to finish the run.