Every 8 minutes, for 40 minutes (5 sets) for times:
Row 500 Meters
10 Jumping Lunges
Run 400 Meters
Modify the workout appropriately such that you get at least 90 seconds to 2 minutes of rest between sets. The intent is smooth pacing and four sets that are very similar in time. If you are running over the 7-minute mark, scale back accordingly.