These ideas can help with teaching Energy Systems.
Looking at Phosphogen recovery and its implications for training. Scenario three groups of students. One student in each group completes 10 x 10 second sprints, depending on which group they are they get between 10 and 180 seconds recovery. The best way Ihave found is to draw out of a hat recovery periods 10 seconds 30 seconds 180 seconds. You can look at heartrate to get data, distance run each rep etc