How I plan to prepare for a 2.49 marathon in Chicago in Oct 2022

I ran a 3h 54 min in New York in 2010 (30 years of age).

A couple of months ago, in Oct 2021, at 41 years of age, I ran a 2h57 min marathon in Long Beach California (my journey to sub-3 is in this story).

I hope to run under 2 hours 50 min in Chicago for which I was approved and am registered.

I’m very pleased with my sub-3-hour marathon but getting under 2 hours 50 min (6.27 per mile pace) is not a trivial challenge. My pace for my Long Beach Marathon was 6.45 min/mile…