Posted: 16/09/2014 at 14:23
I'd just get out there and get some steady miles in the bank.
If its your first half then you cant get any improvement in pace. Obv it will be slower than your 10k and 5k pace - but if you dont get the miles in I expect you'll go pop quite dramatically after about 10 miles.
Yassos could be a start for one session - but run the rest of the week steady at a chatting pace. Do you have a stand alone 10k time to work from ? Work out your paces from that for the Yassos.
I think you could do 12, 16, 20 - you did run 15k almost back to back anyway ?
And I'd also do a medium run midweek so that its not a jump from the rest of the runs to the long one.
If you're still doing the cycling you have to allow for that and not run yourself into the ground.