@rfmaioral I live at 5430' but thats usually the high point of most of my runs. I use 5300' for conversion.
4 Weeks Out
Totals - 7 runs (plus a 10 min shakeout this AM), 87 miles, 11 hours, 3000' climbing
Tuesday - 18 @ 7:54 pace with 900'
Thursday - Better than last year but a good 4 x 2T @ 3.5 weeks out has eluded me for 3 straight cycles. 11:25, 11:27, 11:47 and pulled the plug. I ended up with quite the stomach bug shortly after so that may have had an impact. I try not to get too down on bad workouts and just regroup for the next one (spoiler alert: it worked)
Sunday - 10 min shakeout, 3 mi w/u, 13 @6:01 average with a 5:40 in the middle, 2 c/d. First workout with the vaporflys so not sure if that was the difference, but this was a solid 5-6 seconds better than a year ago. Got a gnarly blister though that I'll have to navigate in Boston.
So now all the hard work is done and I have all the feedback Im going to get. Obviously I'll have to see wind and temp forecasts before making a decision. On one hand, it looks like Im between a 65 and 66 vdot based on the best workouts of late putting me at mid 2:31 on a flat course, mid 2:32 at Boston. On the other, I feel a good 6 seconds ahead of a year ago when I ran 2:35:50, which puts me in the low 2:33s before factoring in last years headwind. 2:31 (Chicago ADP) has more value to me than "amateur glory," so even in the best case scenario, I probably won't join the rest of you in chasing 2:30. And it might take a hot day to discourage me from chasing 2:31.