I followed Pfizinger's 30-40 miles program with a lot of changes. For example, I don't why he adds an long endurance run day after a hard intervall sesion. It made no sense to me since I think it's better to rest or do cross-training the day after. My key sessions during a typical training week
*5x1000m with 2-3 min rest.
*3x10min (about 2.6 km per 10 min) with 2 min rest
* speed session 3x5x300m with 1 min rest between reps and 3 min between sets
* Easy run for 45-50 minutes. The pace was always slow, around 5.00-5.15 min/m or if you rather want it in mile/km (slower than 8 min/mile).
* Longer run for 60-75 min around same pace as easy run.
I avereged around 25-30 MPW.
Before this training approach I ran my best 5K in 18.06. Then I got injured, so I slowly started to jog in February and after 4 weeks I started the doing the workouts mentioned above.
After 12 weeks I'm down to 17.28 min.
*