With a 400 and 800 time like that, you should be able to break 20. I was breaking 19 minutes when I started to run 800's under 3 minutes again. BUT, my mileage was a lot higher than yours. Which leads me to 2 things:
Yezzy wrote:Dennis T Reynolds wrote:100m 14.7
Have you raced shorter/longer races before? What kind of times are you putting up in those?
Mile 6:11 (current fitness is 6:35 as I did a time trail the other day)
1.5 mile 10:00
1) A few others have mentioned it, 45 mpw is low mileage. It's not snobby, it's just facts. It might feel high, probably because all of your peers run 20-30 mpw, right? I've been there, I know a lot of people who are still there. Thinking that because they run 10-20 miles more than 95% of their runner friends that they're running "high mileage". Sorry, but you're not. Start training to hit 60, 70, hell even 80 mile weeks for 6 months straight, and I guarantee you that it will just come down to laziness if you're not regularly running 18:xx min 5k's.
2) You've been through a lot of training plans. Part of the challenge that most runners have is actually not rotating 180 degrees when they don't see the results - usually you just need to make small tweaks, like 5 degrees instead of 180! Find a plan (subjectively I'd obviously recommend a high mileage plan ;) ), and stick to it with the mindset of 2-3 years. Stop changing things up so radically.
Finally, a little more on high mileage. I know a sub-elite female runner who only started running in her mid-30's, she's now almost 40. A few years ago she hadn't even broken 20 minutes in the 5k. Now she's running 16-17 minutes regularly. SHE'S 40! However old you are, it doesn't sound as if you're close to 40. This is just what happens after a few years of good consistent high mileage.