How do get faster?
12 week winter base phase
4 week transition phase
4 week peaking phase
12 week winter base phase:
Lots of easy mileage, with one tempo/longer intervals once a week and some shorter reps once a week. Not much something like 5 x 300m on a grassy field after a easy run once a week. Than twice a week do some short hill reps or strides after a easy run. Tempo/longer intervals i.e. 8k tempo or 8 x 1k or 4 x 2k.
4 week transition phase:
Slowly reduce volume and increase volume of your workouts. I.e. instead of 5 x 300m at the end of a easy run do 12 x 400m and decrease the volume of your longer intervals and increase the intensity
4 week peaking phase:
Drop your volume even more. And increase the intensity.