Workout Notes:
Really try to keep the strict movements strict.
Try to stay moving for the entire :45 sec.
Works best (read: hurts more) if you are exact with your :30 sec rest. 40 sec makes this an entirely different (read: easier) workout.
Breezing the step back lunges couplet? Use weights.
Remember, it’s step-BACK lunges, not step-forward lunges. That is a deliberate programming. It uses more of the glute and hamstring. Touch those knees to the ground every time.