5k and 10k rep help

LintonTravelTavern

Hi folks,

Just wondered if I could ask a few questions on 5k/10k time reduction..

Started running last January (2019).  Set myself the target of doing 10 half marathons, and was happy to just lug myself around doing , for the most part, fairly slowly.  I did a tempo run once a week, maybe five 10ks and a dozen Parkruns.  I was much more interested in trying to get a bit of endurance and get my half marathon time down.

Anyway, did my 10 half marathons, none were amazingly fast, but all enjoyable, for the most part!

April this year picked up a nasty injury that laid me up for a full 3 months.  Started back July.

Wanted to try and have a go this year at getting my 5k/10k times down a little from 20min/47min respectively.  This means practice holding 6.4 and 7.5 min miles for the prerequisite distances, for "PB pace".

There's loads online obviously, but it is all very geared towards track reps, but I have no access to a track or GPS watch.  (Will get one if vital!)

What I have got is a nice exact two mile loop where I live, with measured accurate 0.5 mile markers! 

How would you guys do the intervals though?

I was thinking 10k. I have tried. One mile warm up. The one mile PB pace, One mile easy (repeat x3).  Would 1 mile PB pace/ half mile easy x4 be better?  Or two miles at PB pace/one mile easy (x2)?

5k. One mile warm up, One mile PB pace, half mile easy, (repeat x 2). 

Any advice greatly recieved.