Workout overview
Distance: 6.8 km
Zone distribution
Z1: 0 m
Z2: 4320 m
Z3: 2480 m
Z4: 0 m
Z5: 0 m
Z6: 0 m
Hill workouts are an ideal way to keep intensity up on tired legs. It's easier to add intensity by increasing grade than it is by increasing speed. Running fast requires a fair bit of coordination, which can be a challenge on legs tired from cycling. Use lower speeds and higher grades to hit the target intensity. If you find your struggling, back off on the pace before you back off on the gradient.
On longer duration hill reps like this, you should be able to push into threshold territory near the end of each rep without taxing your legs as much as a similarly intense interval on flat terrain.