with some reluctance, my fastest marasthon has been 2:41. I ran it once, I ran it just out of HS, and I ran it .... 4 1/2 decades ago. My expertise here is, I am convinced that I did run in HS, college and one yr post college. I've read thru the post here and for the most part agree with most if not all of them. I am convinced however that there is one thing that has not yet been mentioned. Its something that is a bit difficult to set up, depending on your circumstances.
I was fortunate enough to train extensively (and exhaustively) with some fairly accomplished marathoners. And this was 'back in the day'. 'We had'two guys who ran under 2:20 (2:15 - 2:17) one @ 2:20, one @ 2:24, at least one @ 2:28 and several others that were at or below 2:20 shape but for one reason or another didn't run the race at the 'right time' or injury or ???. Ya I know, coulda would shoulda -
The element not mentioned here I think is pretty important. FIND SOME TRAINING partner/s that are at or better than what your running now. There is a bit of synergism that transpires when training. And if present during many of your workouts will carry over into your solitary training. I could go on about this but bottom line is I think it is very beneficial - essential? maybe not,. but beneficial very like so. ASK MOST FORMER RUNNERS (COLLEGIATE) AND THEY WOULD (I bet) CONCUR that that was something that 'helped' on a number of levels.
So all of those well thought out and experienced workouts offered here would, I would predict, be easier to do and benefit the psyche as well as the body. The tangibly intangible methinks