Apart from what I stated in the video I just haven't been able to get comfortably near marathon pace in my longer runs and I know from experience that if I can't do it in training I won't be able to do it come race day. I think my basic plan for the next six months will be to do one regular long run, over two and a half hours, every week. One speed session and one marathon pace tempo type run. I want to get it so running 3:45 per K is relatively easy and if I can I know I will be able to pull off something special in my next marathon. In the 10K I did today I did about 4:15 per K and it seemed fast and uncomfortable to me. This is due to some general tiredness and lingering injuries. Perhaps some time off and a couple of weeks of real slow jogging, Phil Maffetone style, will do the trick.