150 Step-ups 25/15. HEIGHT IS VERY IMPORTANT!! Knee stays right at or below hip crease.
Be sure to alternate legs on the up & down
No hook grip on the dumbbells
Use the muscle of the leg on the box to complete the step-up, not momentum.
L*-Reduce Reps as needed. Set a goal. 75 for example. Or set a Time cap.7 Mins for Example.