My PB was 2:56:34 on a certified course (Ocean State).
I think the most boring 'thon is LI---flat as a pancake. It's mostly run on the Wantagh Parkway. I entered it right after I ran Ocean State for the last time, thinking I could get under 2:50 and qualify for Boston. Obviously I was still delusional after crashing and burning the last 6 miles of Ocean State

Needless to say, I ate the entry fee and hung up my racing shoes. I ran a bit during law school but never raced again.
I used to scoff at "the Wall" until those last 6 miles. I hit 20 miles at 1:56--do the math on the last 6---10 minute miles
Some photog shot a picture of me somewhere on Ocean Drive, maybe the 22 mile mark. I ordered it and put it on my wall just in case I ever felt the urge to mount a comeback
