[quote]Dennis T Reynolds wrote:
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
With a 14.7 100m you have sufficient natural speed to break 20. Looks like your weakness is aerobic. I would build up weekly mileage to a consistent 50 a week. Mostly easy running with 2 to 3 hard sessions a week, long run of 90 mins. What worked well for me when I was sub 20 was 1) 10 to 15 x 200m at 35s 200 walk recoveries 2) 3 or 4 x 1000m at best effort 5 mins recovery 3) under distance race weekly 1500m or 3000m. If you haven't got weekly races then do serious time trials.
Be patient. You will have breakthroughs. Like taking a minute off 5k time etc. Don't rest up for weekly races, only for a serious 5k race.