Any advice on structuring training blocks for Half Marathon?
I am after some advice on how to structure my training block(s) for my first Half Marathon, which is 36 weeks away. I am just coming to the end of a 10K training plan, which I am running as a time trial this weekend. So over the course of the 36 weeks, I need to do a 10K -> HM distance transition, and then I would like to do some improvement on my HM time.
I was thinking I could do this either as three 12 week blocks, with the first focussing on increasing distance, and the next two focussed on improving my HM time, or as two 18 week blocks (distance increase and then speed improvement). I'm not sure which of those approaches would be better, or if there are other approaches I should consider? Would be very grateful for any advice on how to structure the training.
Context
I am a beginner runner, having started in February of this year with C25K. I am just in the final week of a 5k to 10k transition plan, which I did over 17 weeks (I probably could have done this over a more condensed period in retrospect). I have been using Runna (I know) to design the training plan - to be honest I don't really use the 'AI' coaching, but do find having a defined plan, that tracks my runs with a nice UI helpful in keeping me accountable.
I expect to run my 10K time trial in ~55mins (Garmin predictor says 53m30s, but I take that with a pinch of salt). My aim for the Half Marathon would be to complete in sub 2 hours, which I think should be achievable. My longest run to date is 12km. I can only run 3 times a week (generally 1 easy, 1 speed session, 1 long run) due to other training commitments (strength training is my priority).