I live in the Portland area and typically race the Shamrock Run 15K or Half Marathon on the weekend of March 17 - four weeks before Boston. This is a very hilly course so it is great training for Boston - especially the downhill coming back towards the finish. My question is, is four weeks out too close to Boston to run this race all out? Would racing the Half or 15K be more beneficial? Or would I be better off running the Half at marathon goal pace? For reference Suguru Osako ran the Half last year in 64:10, then went on to place 3rd in Boston in 2:10 - so he ran close to marathon pace at Shamrock.
Opinions seems to be divided on this - any advice?