Regarding the work that I described for John Korir, the difference between sprints uphill and "ramps" (or steep slope) is in the gradient (about 10% for sprints and circuits, and 30% or more for ramps). Also the mean is different : we use circuits for STRENGTH ENDURANCE, sprints (not during circuits, but alone) for RECRUITMENT OF THE HIGHER NUMBER OF FIBERS, ramps FOR FUNDAMENTAL STRENGTH FOR A RUNNER. In this case, ramps replace training of weights. When you go for a training having like goal the improvement of STRENGTH (not Strength Endurance) or SPEED, you must use very high intensity (near the max) and recovery is very important, because you must be fresh. Your goal, in fact, is not ENDURANCE, but the ability to work at max intensity for your muscles. So, recovery after every ramp (but also after every sprint climbing) must be FULL (may be also 2min or more, depending from the length of the sprint, that in any case never is longer than 100m, normally 80m).

How many hard workouts in a week ? I use normally 2 very hard workouts, not in the same direction. But I want to remind that there are many levels of intensity, not only very hard workouts and regeneration. An example of weekly programme for an athlete of 13:30 (may be European) during the Fundamental Period :

MON
a) 1 hr progressive running from 3:45 to 3:25 per km
b) 40:00 easy + 10 x 80m sprint uphill

TUE
a) 30:00 easy + 8:00 / 6:00 / 4:00 / 2:00 / 1:00 fast recovery 2:00 moderate (about 4:00 per km)
b) 40:00 easy + exercises (skip, bounding, running in frequency, running with long strides)

WED
a) 1:20:00 at 3:45 pace
b) 30:00 easy + 4-6 km continuosly running uphill (80% intensity)

THU
a) 50:00 easy regeneration
b) 50:00 easy regeneration + stretching

FRI
a) 30:00 warm-up + 4-6 circuits lasting 4-5 min (uphill)
b) 1:00:00 easy regeneration

SAT
a) 1 hr with short variations of speed
b) 40 min easy

SUN
30:00 easy + 12 km at 3:05 pace