I ran Tokyo Marathon this past Sunday.
I executed pretty well on my plan. I did my weird run/walk tactic which seemed to help me make it to the finish line on limited training, and which seemed to puzzle so many spectators and other runners. I ran 4:30, then walked 30 seconds, ran 4:30, walked 30 seconds, etc. from the start through about 33 kilometers after-which I only ran through to the finish. The first couple walk breaks I found the course extremely crowded but after a few kilometers I had plenty of space to walk without interfering with the pace of surrounding runners. I was surging pretty strongly off the walks. At one point around 25-30k I had fantasies of dropping below 4 minute per kilometer pace and breaking 3 hours. But around 32k my legs started feeling really bad. I wished I could switch to swimming or biking (or sitting) for awhile. I am glad I did the run/walk thing as annoying as it can be. If anything I might have been better to have taken walk breaks all the way to the end. I plan to resort to the run/walk technique again in future runs, though hopefully not frequently.
Here are my splits --
