The runnersworld training calculator generates a marathon plan with long runs at increasing pace -- I got 14,16,18,7 at 8:08, then something like 16,20 at 8:03 -- I don't recall the details, but over the 16 weeks, it stepped the pace up by 5sec per mile faster four times over the long runs, I think. Is this a common trait in marathon training, to slowly increase the long run pace? Actually, I think the training plan generated increased the pace across the board of all runs, four times (from 8:08, to 8:03 after maybe 4 weeks, then to 7:58, then to 7:53, I think).

Makes sense - but, 8:08 is faster than I'm accustomed to doing my long runs, so going down 15 seconds from there may be significant enough to matter to me Thanks for the feedback.