400 m run, 4 perfect lunges, 4 inchworms
Answer this question:
When I get tired, the first thing that breaks down on the run is: _____
Now, spend 3-5 minutes on a drill (or two) for that running weakness.
Rest-work ratio is 1:1. That’s plenty of rest and not a huge volume so each interval should be as fast as your form allows! Keep track of what breaks down and when as well as your time.