You can also use a regular step for this workout, but I do not recommend using a BOSU for this one. You are going to work through a series of 3 lower body exercises on an unstable platform:
  • Squats
  • Lunges
  • Step-ups with an overhead press
All of these could be made easier or harder depending on how much weight you use and where your client holds it. The higher the dumbbells, the higher your center of gravity.

For squats and lunges, holding the dumbbells at shoulder height makes it harder. Removing the dumbbells and doing body weight only would make it easiest. For step-ups with an overhead press, of course you would not attempt the press if the client is too unstable.