Endurance (Option 2.) Workout

A.
Warm up:
5-10min.
Including 3x 30s hard pace sprints
+ stretch

B.
10x
1min: 110-125%/20min. avg
1min: 50-60%/20min. avg / Rest

Rest 5min...

3x
20s. All out
Rest 2:40

C.
Cool down:
5-10min.
+ stretch