Hi
Interesting thread as this is also my mid term goal. I am a bit faster than you (36:30 - 10k, 17:30 - 5k) but i also improved from 38:00-39:00 over the last year.
What i did:
- (Approx 35 km / week - i want to bump it up slowly i think 50 km or more would be better)
- 6 runs per week
- 3 weeks increasing - 1 week 50% volume
- most weeks 2 sessions on the track (1 focusing on speed 8x400, pyramids 200-400-800-1200 and down and so on, 1 with longer intervals like 5x1000 or 3x1600)
- sometimes i replaced the speed sessions with hill Sprints (10 x 12 sec uphill)
If you really want to give it a go i would add the following (which i am too lazy to do regularly)
- 1 x LR 1:30 to 1:45 hrs
- 1 x Tempo 30 to 45 min at HM pace try to stay relaxed and smooth
Maybe it would also be better to keep the rest shorter on the longer reps (for instance only 1 Minute between 1000s - i do 3). I will try this in the future - to run the intervals slower. Also maybe run your easy days easier (i run them between 5:15 - 5:30 /km). And I found it helped to do core 3x a week, and 2x a week some strides after easy runs.
I would be happy If someone with experience could give us amateurs a bit of Input ;) i wish you all the best for reaching your goal !!!