I dropped my times from 3:56, 3:24, 3:23, 3:11, and just recently 3:09:25 last week on a fairly hilly LA course. Im 40 year old male,married 2 kids, full time job.
I followed Pfitz 18 week 55 plan from his advanced marathoning book., so my max week was 55. Im about 175 lbs so not really thin for a runner.
I think some of the biggest differences this time was I kept the intensity up during the taper just cut back mileage a little bit. Carb loaded much better. Took enough gu and liquids throughout the race. Plus got lucky with ideal weather. My tempo runs and intervals were also faster than last cycle, and kept the easy days easy , sometimes as slow as 9-9:20 pace.I did a couple 10k tuneups as well.
I did I think 4 MP runs of 8, 10, 12 and 14 but that 14 mp 18 mile total - 5 weeks out was a big confidence booster..
higher mileage should def help, I know 55 max is minimal really, but it sometimes is the quality over quantity. I also was pretty dedicated and didn't skip any runs I think consistency is the key.
Started slow and actually had my 26th mile my fastest of the whole race at 6:46.
Any way good luck. I know I am not super fast for this site but that is what worked for me.