Is this Friday's 5k on the same course? or a less undulating one?
19:40 is quite an achieveable target based on your last time, though in reality 20 seconds could be made up or lost just on something as simple as what/when your breakfast was, or when you last took a dump! ... Sorry, I guess that could quite easily be mis-interpreted... what I mean is that if if you ran as hard as you physically could for two 5k's on teh same course, if everything comes together for you in terms of weather and how you feel etc, you'll smash whatever time you'd manage if you had a bad day - regardless of what your percieved effort level is!
Aim for 19mins, don't expect to manage it, but just get as close as you can ;¬) perhaps pace yourself for 19:30 and pick up the pace if you feel able?
I've been reading into training for shorter distances a LOT while i've been off, and have decided myself to concentrate on shorter distances... the general thing I've picked up (and it sounds pretty basic) is that to get a good 10km time, you need a goo 5km time, for a good 5km time, you need a good 3k, and you can;t have a good 3k time without a decent 1500m time!
Once I'm back up to fitness, I'll increase the amount of speed work I do to include more training at 3k, 5k, and 10k pace. If 5km is your goal distance I'd perhaps swap 1 or 2 of your 5mi runs for a 'quality' session, be that short fast repetitions, tempo, fartlek or some hill running.
as always... Just my thoughts
