Spring marathon season is the most over-stuffed part of the running calendar. Five Majors in twelve weeks, plus a hundred excellent regional races. Picking three to actually train for matters more than picking ten to enter.
Our pick for a fast first marathon: Valencia. Flat, predictable weather, world-class organisation, achievable entry. For atmosphere: London — unparalleled crowds, brutal entry odds. For an undervalued midweight: Manchester or Rotterdam, both consistently delivering PBs without the lottery pain.
If you're chasing the World Marathon Majors stone, Tokyo and Boston bookend the spring window. Both reward years of build-up — Tokyo through the lottery and Boston through qualification. Use Racendo's series tracker to keep the progress visible.